You're right that solely having porn as your sexual guide can lead to some serious disappointment and confusion. I don't think anyone here was suggesting that, or that ALL porn can be informative.
But this comment only shows one case where someone gets an only partially informed idea and takes it the wrong way (and only watches one video?). It doesn't address any of the other cases where it is helpful.
Also: many of us enjoy more than "wholesome" love making, and porn can be a way of discovering things you never would have realized you enjoyed.