Okay? Who cares? Riot never claimed that skins do anything other than give your champion a fancy coat of paint. Barring a handful of hitbox weirdness and coloration issues on certain maps, they provide no competitive advantage. They do not have any inherent value past their appearance either (though it can be argued that certain skin's rarity is interesting, it never merits anything more than a "huh" from people). Nothing different was ever claimed.
I buy skins because I want my champ to look cool and I want to give back to riot a bit for giving me a game that I've spent loads of time in. If you don't want to, sure, but don't spam the boards and forums with "I am so smart for figuring out that skins are not a good investment."