You're joking, right? StarCraft 2 has way more units than your average RTS (of that type) and the current state of the metagame gives players plenty of options (except maybe in Protoss v Protoss). Have you ever watched a pro game? They're always about scouting to see what your opponent is planing, and a rush for resources is hardly the only strategy since whether you expand early or go for an early push is a decision you must make every game.
Ach, no, don't bring metagame into it. You can turn anything into a travesty of metagame.
I understand both points though. Starcraft 2 is a very well balanced RTS, no doubt at all, but it's strategy lies in very specific and very small things. Like which second of the match you build your Warp Gate in, or how many SCV's you build in the first 2 minutes. Those kind of things end up being the deciding factor in skirmishes, and while there's lots of room for variation in there, it has a rushed feel.
Starcraft 2 matches are short. Maybe intentionally so, as it only takes about 15 minutes to reach full potential and end a match. We've all seen them ended in far less time than that.
Then there's the reference. Age of Empires II. It takes a good player at least half an hour to reach the imperial age, and even then it's not always the best strategy to rush for it. You have an entire economy to consider of food production, wood production, stone and gold production, and you have to balance it with the population of your villagers and the size of your territory and military. Games can completely turn around at any time, even in the late game. I've had AoE2 matches where my entire base was destroyed, and I STILL managed to cobble together enough of a rebellion force to outlast the rest of the players, cutoff access to 1/4th of the map, and guerrilla my way to a noble defeat. You can't do that in Starcraft 2. If you get wiped out at the base, it's over.