A lot of players simply dont expand, they spend time idling around and then look to the easta dn see their ally has expanded 5x as much as them and they're like wtf. And their allies like "while you were chatting/idling/watching features sway, I was sending units out to cap empty mex spots." 30 mins later "this maps crap, the economys so slooow" looks to the east "wtf how did you get all of that" ally replies "well when you were idling I built units and got my economy going faster, and I expanded, so now I'm on an exponential economy while your still wasting time capping mex spots."
Its not that a maps too big
Its that the players strategy is too small slow and closeminded