It was that Fender went on with only a B-Bender, when Clarence's guitar pulled all 4 middle strings.
Completely incorrect.
First, Clarence's guitar had a bender made by Gene with parts from a "donor" Fender 800 he got from Sneaky Pete. It was one of Sneaky's "parts" guitars for his 400.
Gene installed four fingers from the changer - which was a short-scale changer, not like Sneaky's earlier model 400. They played around with different pull for about a day before settling on the "B" string; the "E" is an easy finger-bend, same with the "G" (which also works well in chords with the other fingers in place); the "D" was a non-player right away. The "B" was most logical because it was the one used the most for chimed behind-the-neck bends in "A". worked with a D7 chord to pull up to a major, worked for double bends with the manually-bent "G" and was the easiest for counterpoint stuff using the B bender and E string fretted in different directions.
So "B" became the only one he ever used, and always set for a full-step. That guitar has a 1 1/8" throw - very long compared to what came later.
Bob Warford, a good friend of Clarence's and former bandmate, had Clarence's old white Tele and designed (with his dad and some engineering students) his own version - somewhat similar, but a MUCH shorter throw...less than 1/2". It's like playing an on-off switch until you get used to it (I've played with Bob many times and messed with...and taken pics of the guts of...his guitar).
That was it for a short while, until a non-playing recording engineer/machinist named Dave Evans began making "Pullstring" guitars - the first slightly crude B benders, but gradually pretty refined. they were known for their butcher-block bodies; that's what Bernie Leadon used on the Eagles' first album; Al Perkins still uses his; Albert Lee has one as well. About a hundred or so were made out of Dave's shop in Torrance, CA. Dave's design sort of accidentally morphed itself into a 5/8" pull, which became the de facto standard for shoulder-strap benders.
Then Gene, after the Byrds disbanded and Clarence was killed, eventually decided he wanted to start production of his own design (different than the Evans and very different from the original). He and Dave were friends (Dave had also been working on a guitar for Clarence when Clarence died - and Dave burned it in his fireplace)...so Dave, who had a "real" job anyway, stopped production out of respect for Gene. Gene initially even called his benders (installed in other's Teles, primarily...although he did some odd ones like a Les Paul for Jimmy Page) "The Parsons-White Pullstring". But so many people called them generically "stringbenders" that the name stuck and he adopted it.
Interestingly, there's a patent on a device granted to Gene Parsons, Clarence White and Eddie Tickner (Byrd's manager who paid for it) and other potential makers stayed away from Gene's "patented design".
Except the patent is for the ORIGINAL one based on a pedal steel changer, with a totally different mechanism than his production bender!
Leo Fender knew this and developed his own (which HE patented) - which was OK, but they were mounted on an awful "Custom" Fender made of castoff parts. There were at least two prototypes, and although he wanted it made CBS management said no (a local guitar tech here owns one of them...and the bender plays well, but the guitar IS awful!).
A few clone makers popped up but never made a dent. Joe Glaser and a few others began making different designs with less routing and a shorter throw, which were/are popular with the Nashville crowd while Gene's always held sway with the country-rock and rock crowd.
Then an installer in Virginia, Mike Nihen (a monster bender and dobro player), owner of the Stringpull Guitar Shop, started modifying Parsons-White benders into long-throw benders to match Clarence's (he got the measurements from Marty Stuart) - eventually installing Red Rhodes' "Velvet Hammer" pickups and making the "Nashville West", with the long throw, a double thick body (but fake..the bender was in the usual route but the extra chamber gives the guitar a unique resonance), and the same relic-finish, stickers and even the Plymouth Satellite logo Clarence had on his. He made 42 or 43 before the pickup supply ran out, and they were, to him, an integral part of the guitar (and a huge part of getting Clarence's tone IMO, having had a few pickup sets and owning the Nashville West prototype).
Gene was unfortunately kind of upset...but it seemed as if his ex-wife who ran the business was really more upset than he was. Gene started making long-throws as well to satisfy the demand; as h put it after deciding it was good thing: "there's a lot of music in a long throw".
Eventually Gene's patent expired, and machinist Bill Bores began making clone parts at a lower cost, building quite a market. Gene, manwhile, had developed the "Parsons Green" (named with his ex-wife) bender and licensed it to Fender - that's the bender in their production guitars. Now Hipshot produces the Parsons-Green ( slightly improved model) under license.
So the "Fender" bender is actually a Parsons...and made completely different from either of the other two as it's attached to a rear plate as an entire unit (although it's closest in function to the original, with a rocking cam instead of a turning hub).
Meanwhile, some of us had started the Clarence White Forum - a bunch of So Cal and other bender players, including Bob Warford and several other "original" players. Murray Cullen, who started the forum, had an exact clone of Clarence's bender (minus the electronics) made from a Custom-Shop Tele by Gene, who got hold of every tiny detail from Marty Stuart and his tech. It plays and feels almost exactly like the Nashville West, which pretty much legitimized Mike's design (and the guitars, when they are sold at all go for a huge sum...plus Red's pickups...just the tapped bridge alone...sell for $4-500 each!)
Meanwhile, back at the farm..
...some of us..mainly me, who lived near and hung out at the same studio Evans did, although we never crossed paths, were hunting for Dave wondering what he was doing...and wondering if he'd be interested in making a butcher-block bender or two like the old ones.
Dave's not a computer-guy, but still builds studios and has an incredibly-equipped, modern machine shop in northern CA. He got a computer, got on line, learned how to "google"...and found the Clarence White form, posting "I'm right here!". We chatted and it turned out he was interested in making benders again for fun...he had talked to Gene and Gene was fine with it - Dave didn't want to offend his old buddy.
So somehow I ended up with the prototype of his new design in one of my guitars so I could beta-test it; we made a few changes and additions, and he's back in business making Pullstrings...including working up to maybe an old-style butcher-block body or two. his design has gone beyond any of the others - with adustable spring tension (you have to move a screw and guess with the ones you CAN change tension on...or change springs...but this one turns with an allen driver in seconds. And he also has three different pulls built into the same bender - 5/8", 1 1/8" (long throw) and one I came up with in the middle - 7/8", which to me is the "sweet spot" nobody did before and I use all the time. I posted pictures of it in another thread.
So - there's your history lesson for the day; and no, Fender didn't make a mistake.
Lastly - if you play a bender...please don't try to play fake pedal steel on it...it's a different instrument. Listen to old recordings of Clarence (especially from about 1970-on) or Warford - they are THE guys.