So I've noticed you get a "favored" bar at the start of each game. Do you think this is good or bad? I think if I would've seen my opponent favored around 75% I'd most likely cheese or just altqq out within the first minute (if it's still a draw?). This would also affect my tactics and mentality when playing. On iccup, you can easily check the other player's location and stats. It's good to know that you're playing against a player in the same ladder as well as country, but I feel that the favored bar is nitpicking.
If you are on team A, but team B is favoured, then team B is expected to win, so it's their reputation at stake, not yours. This would be worth playing because of the experience points up for grabs. If you win, you get lots, and if you lose, you don't lose many. Which is a great opportunity for you. For team B however, if they win, they don't get very much experience, but if they lose, they lose lots. Trust that the matchmaking system will fairly reward or penalise you, based on statistics and expectations.
So big losses and little gains for playing people much worse then you. And small losses and big wins for playing people better then you. So if the losses were too great then no one would want to farm the lower players. Just not worth it. But it'd also make finding a higher ranked player hard as they would not want to play against you. So to get any games in at all you'd be forced to look for others around the same level as yourself. And I think this is just what Blizzard want us to do.
You don't look for other players at all. There is a matchmaking system that sets you up with someone relatively close to you (though generally there will still be somone who is slightly favored).
