@whule I completely get what you're saying, but I think it'd be nice if NameMC showed the original wearer of the skin/first person to wear it on the page for the respective skin. I would be pretty annoyed too if the original skin i've been wearing for years was taken and someone else got credit for it. I know it's just a skin, but it's still an art form, that's all i'm saying.
It does do that. People just modify them slightly and then re-upload them.
Mojang says in the terms that skins are meant to be shared and if you upload it to their website then you do not have rights to stop people from using it, so we don't enforce it.
We intend to eventually have a way to upload skins on their own which will give people more obvious credit for uploading them but there's still nothing stopping people from uploading skins from other sites or modifying them.
(And this is far from unique to NameMC, there are dozens of MUCH larger skin websites that also let you copy skins and don't enforce copycats or theft of skins.)