I used Smultron for yonks as well; very good app.
One thing I like about neovim (and its taking me ages to learn & improve) is being keyboard first and having less time with fingers away on mouse etc, its helped my concentration, as has full screening my terminal session and not having anything pop up in eye lines!
It seems like BS eh. Other folks I've seen are suggesting its just because they want to ditch easy anti-cheat to go with EA anti-cheat which (apparently) is windows only with no plans to develop for linux.