Regardless of superior performance (on Windows), most OS'es in combination with most games spend sometimes up to 30 seconds just switching between a fullscreen application and a windowed application. If you have two screens, or, in general, you're the kind of person who does more than one thing at once (most people), this is just a pain.
Blockland is not the kind of game you'd be engaged in full time, either.
it takes my computer maybe like 5 seconds max to apply all settings, so it's no problem for me
and I the last point is fully an opinion, I get very engaged in pretty much any game / I use steam overlay for internet browsing while gaming