I agree with you. Things like tubing, racking canes, etc. make a lot more sense to me. Wild beers are a secondary element of this hobby as they tend to age so long. So I 'hand' down some of my plastic and vinyl. I rather think of it as dedicate.
I am not sure anyone is saying not to treat the gear any different - all should be clean and sanitary. Most are afraid of the risk of contamination in a clean beer - so if the 'clean' fermentation bucket develops a bacterial infection (but otherwise in good shape) it makes sense to use for sour beers. I still have some Speidels, and an unintentional contamination in one, but I cleaned it, sanitized and replaced the seals/spigot and have run clean beers through it many times. All my stainless, I keep separate TC gaskets for wild beers, and autoclave the stainless fittings after.