I don't think the issue in this is really your level. Sadly, a lot of people just operate in their own little cliques. Others are only interested in RPing with sexy catgirls. Why these same people have "Walk-ups welcome" in their Search Info, I've no idea, but it happens. Maybe it's been in there since before their clique was found? Maybe it's only there to encourage sexy catgirls? Who knows?
At any rate, being level 50 will give you more clothing options to make your character look more appealing, as well as help people know you're more likely to be someone who will stick with the game for a while and make interacting with you worth their time. Sure, it can make you more appealing to RP, but I don't think level is the issue.
Some people are just absorbed in their own friends/interest, and their friends they've likely known in game for a while, hence are probably level 50 by now.
At any rate, being level 50 will give you more clothing options to make your character look more appealing, as well as help people know you're more likely to be someone who will stick with the game for a while and make interacting with you worth their time. Sure, it can make you more appealing to RP, but I don't think level is the issue.
Some people are just absorbed in their own friends/interest, and their friends they've likely known in game for a while, hence are probably level 50 by now.