That’s me, for example. I find colorful skeuomorphic icons way easier to differentiate than black-and-white flat ones. Way faster, in the first place. Especially if I don’t know the context (app, menu, etc.) very well.
Yet still both are definitely better than text only. Using new GIMP 3.0 RC2 is extremely irritating for me, close to unusable, because they removed icons from their vast and numerous menus. I hope KDE doesn’t go that way.