Well you don't have to recruit all of the characters, just the required amount until the game lets you proceed to the next plot mission (Horizon, Collector Ship, Reaper IFF, ending). And in some cases, Loyalty and N7 missions also count towards that mission goal. So if you don't HAVE to do all the recruitment missions, doesn't that make them sidequests too?
So suddenly ME2 is a game made almost entirely of sidequests and it's an argument of semantics. <_<
Personally I considered Loyalty and Recruit missions to be the "main plot."
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You have no time to ponder such questions, as Link has just grabbed a Smash Ball.
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