There's no such thing as "politics-free". Everything is political. Are you going to ban also comms about veganism? climate? LGBT? even gaming is political (just look at the cringelords of gamergate).
On top of that, you don't know is the person who is interested in lemmy wants to join a "status-quo" instance like that or not. What if they were hoping to talk about some political subjects and now realize they cannot without making a new account? Bad experience.
There may be a point to be made about defaulting users to comms with less potential for flamewars, but that would require some sort of backend update.