Games like XCOM and some RTSs and RPGs require turn-based combat, because real-time would be too hectic or simply wasn\'t a option.
XCOM is something of a RTS game about tactics, and turn based makes that part of it shine - if it was RTS it would be just as good, though there are some monsters that can move for VERY long periods of time and are VERY fast, so if there was no turn-based system, these enemies would over-whelm you quickly.
Now imagine XCOM as a MMOG. Where there\'s a timer and if they dont choose a action their round ends, and their enemy\'s begins. because 1 \"unit\" in XCOM can\'t occupy another tile with another unit on it, all it would take would be 2 players to be AFK in the exit from the dropship to stagnate gameplay. Or when a player is AFK, and is the last one alive... or when you\'ve run out of ammo...
Turn based works for some games, but not for MMO ones.
