First, placement games mean a lot. They give you the definition of your ranked season, and if you go 50% win rate in them, you'll need to have a much higher win rate to get a high Elo.

Second, game amounts. In S2, you were +38, with a 610/572 win-loss ratio. The General is +66, 981/915 win-loss ratio. He's played a significantly larger amount of games, and he probably won his placements.

Let's assume you went 50/50 in your placements. You were around 1200 Elo, maybe 1150, maybe 1250 after them. If you assume an average of 12 Elo per game, you get 420 extra Elo from your wins over losses. Of course, you don't gain exactly 12 Elo per game, and it's probably lower - so we're looking at what, 1400-1450? Since you say you're Silver, that makes sense.

The General, however, probably went 9/1 or 10/0 in his placements. This would immediately put him a few hundred Elo above you (1600~ or so). Add the 66 wins at 12 Elo/game, and you get 792 extra Elo from wins over losses, sticking him at about 2.4k Elo. That sounds about right, does it not? Also, because he went 10/0 or so in his placements, he can have a 52% win rate and be a high Elo player - because he already has a good starting Elo, and he started strong. Also keep in mind that he probably didn't start from 1200 Elo - he was probably 1500-1600, so he (probably) won a lot of his placements and got stuck near 2k at the start of the season.

In short: He has a 52% win rate over a far larger amount of games than you do, and he probably did much better on his placement games than you did. The system works properly, over a large number of games. It won't work properly over a small number of games, because of the way the game works.

I myself am +100~ or so in normals, which would stick me, theoretically, at about 2.4k~ Elo. Clearly I'm not 2.4k, since I get matched in normals with 1400-1700s, and the occasional 2k+er.