> I doubt one can even find non-glatt at a reputable butcher.
I think it was due t hashgahot moving to get the market from more observant community, so they stopped certifying non-glatt. That lead to, obviously, lack of non-glatt meat from reputable companies. Presumably, it is easy now to sell non-glatt to non-kosher market.
I think the picture was different in previous times when local butchers were in charge.