Nay because anyone can make an account here who has an account elsewhere. In practice it makes absolutely no difference unless we somehow restrict account creation here which I also say Nay to doing so.
I think it matters. It's not about practical difficulty - it's a mental barrier
If you make an account here, you're a member. Doesn't matter if you have 4 other accounts on other servers, the minute you sign up this becomes one of your servers
It's a very low bar, and a very open community. But I think you should have to actually join it, so that you feel invested in it