Basically, I agree with Donny. I don't think pedal steels are particularly expensive, and definitely not expensive in constant-dollars, as compared to back in the heyday of pedal steel - let's say 1960s and 70s.
I wanted to buy a starter steel back in 1973/74. It was $450 for a Sho Bud Maverick and $700-1000 plus for a pro-level steel, depending on various factors. It would have been at least another few hundred bucks for an amp loud enough to make it sound right. For maybe double that, you could buy a really nice new car. Totally out of the question for a lot of people back then, and definitely me, broke-college-student-on-scholarship doing full-time co-op jobs 2 quarters out of the year to pay the rest of the bills. No car, no cell phone, one $75 1965 Fender Mustang with a small amp, and definitely no money for a pedal steel. IMO, it's a lot easier to put one's fingers on the kind of money needed to get working pedal steel setup than it was back then. I taught at Penn State for most of the last 30 years, and most of my students have had
far more disposable income (in constant dollars) than virtually any of my peers back in the early 70s. And relatively easy access to loans. Yes, there are some students barely scraping by, but go to most major college campuses and you'll see a very different picture than 40-50 years ago. Lots of cars, expensive cell phones, credit cards, and so on.
You can see why using the Bureau of Labor Statistics' CPI Inflation Calculator - e.g., the inflation factor from Feb 1973 to Feb 2018 (45 years) is about 5.8. In other words, $1000 has about the same "value" as $5800 now. Or looking at it a bit differently - one can get a pretty good steel (either a good starter like a Zum Stage One or one of several older but solid professional steels like a BMI, MSA, Dekley, or occasionally others) plus a loud, clean solid-state amp for about $1200-1500. Any new car is 10x that. Even at the high-end of that, this is still less than $300 in 1973 dollars.
As far as financial risk goes, I realize you need to be knowledgeable to know this - but in fact there is very little financial risk to buying a good-quality but inexpensive pedal steel, if you do it intelligently. It's pretty straightforward to sell a good-quality entry-leel steel for about what one pays for it - and if you buy right, sometimes even more.
So I really don't buy the argument that money is the main impediment to starting on pedal steel. Rather, I think it is ignorance of the instrument - what it is, what it does, how much they cost, what it takes to learn, and so on - by the general public (musicians and would-be musicians). Steel guitar, and especially pedal steel, is and has always been a niche instrument, and its players form a relatively tight and small community.
I also note that there are quite a lot of younger players who are learning and playing in bands - especially Americana, indie-rock, and so on. This forum maybe used to be fairly representative of steel players, but I don't think that's true anymore. Somebody is buying all these lower-cost steels like the Stage One, Encore, Mullen Discovery, GFI starter, and so on. They're building quite a few of them. OK, it's never gonna be like selling Squier Affinity Strats for $100-200. Thankfully, IMO.
So - is there a "need" for more builders? I'd say not a "need". But I think there's always room for another if they're willing to build a good guitar and don't expect to make a ton of money. In other words, building pedal steels is, and probably will continue to be, a labor-of-love, to a large extent.
Ever been to a Steel Guitar Convention? Why on planet earth ... new country music is just noise? How welcome are Robert Randolph fans here?
I agree with your other points, and this one to a point. But I do think there are quite a few younger musicians taking up pedal steel who aren't gonna be active on this forum. Sometimes they don't know about it, and sometimes they're turned off by the attitude here. But they're still buying and playing pedal steels.