Not to turn this into a pissing contest, but Canada's internet is far more shite and far more captured by an oligopoly. Independent ISPs are harder to find than competition up here in the North.
As for who is losing money, I think you're also correct about that. Both the sportsbook and losing bettors will subsidize the "sharp bettor".
It's also worth noting that some sportsbooks (the more well established ones like Caesars and Pinnacle) do limit all players equally. That's because the do as you say and act like a marketplace to pair up both sides of the bet.
The problem with entertainment books is that they often pick a side on the bet so each side is not equally balanced. An attempt to maximize potential profits for themself instead of the traditional strategy to minimize their risk.