You can play all the races in each game. The campaign is hardly necessary to learn them. Some good RTS games anymore don't even have campaigns (Sins of a Solar Empire, Demigod).
Half-Life 2 was not remotely a complete game. The ending was not the ending of Half-Life 2. No, they expected you to buy 3 more games to get to the ending, and we still haven't gotten the last game (4 years down the road). We'll get the other 2 pieces of the Starcraft campaign much faster than that.
You all overreacted to a situation before you took the time to think it through. As a PC gamer I'm embarrassed to see such reactions from my fellow gamers.