As someone who spends a majority of time in games roleplaying, I couldn't care less about what other people have so long as it fits in with the lore and aesthetics of my own characters. Most of the game's PvE/WvW/PvP could go away and I'd still log in to RP and customise stuff (though I do enjoy PvE, so I'd be spending MORE time in another game to fulfill that want). Heck, I have characters that don't have any lore or personality or what have you, but I still buy cosmetics for them to look neat when I log in to play them every so often. It means different things to different people. I know RPers are not the biggest group of players, but our reasons for working towards skins might simply be because it works for our little part of the story. Sure, you could write with others on things like Discord through text only, but it's fun when you can show your RP buddies almost exactly what your concepts look like in your head, on screen.