Why cant you change your P@yP@l name?

Im needing to create a p@yp@l so i can get paid for doing work for people.

But i already had an account i used for inappropriate reasons and my username is clearly sexual related and that would be so awkward to babysit kids for someone and be like "Yeah sure send me $ at SexyBunnyXOXO"

And for some reason you cant change your Username??? Like why?

So it made me need to create a new one so that awkward scenario doesnt happen but it's such a hassle