I do understand wanting to keep your online identity small. Still frustrating though :p. (And I have been in a situation where people caused me trouble here on LJ, but surprisingly they never made the jump to my dA. Nowdays I guess the story might be different, but I try to avoid causing any drama to begin with. :p)

I think another thing is that if I were to come across your name on another site and there was nothing to connect it to any of your other known sites or contacts, there could be a question of whether it was truly you or an imposter. Which I have run into before.