I don't agree with bookies always win. I mean, I agree with it, but not on the expenses of the players. At least not on the expenses of those that know what they are doing. They always win because the odds provided, are of course controlled and ranged, that they always win no matter where you bet, as long as they can keep the wages balanced as well.
It's the same as trading in exchange markets. On that case bookies also charge a commission since they are not the ones controlling the odds.

The reason I say I don't agree, is because if you know where to bet, you should still get some profit. Not as much as you should, and that can affect how much you earn in the long run, but you should still get profit.