Thirty years or so ago, when a crimini (common brown, cultivated) mushroom grew too large, the growers would toss it because even though the taste remained the same, the texture was rubbery and they were just too unfamiliar looking, too mutant, too toadstool. I don't know which came first -- the idea of grilling them whole and using them as vegetarian "burgers," or the idea of renaming them "Portobello," but they came at about the same time.
Even though they keep you in the dark and feed you BS, there's hope.
Rich