This is how business should be and if there's really a cases that they drive out the winners then maybe they are a scam casino and doesn't want their gamblers to win so we should avoid that.
You clearly have no idea how sportsbooks function. Most sportsbooks are considered soft sportsbooks which implies that they don't like consistent winners and chase them away by limiting their bets.
Only few books are considered sharp like Pinnacle, Bookmaker etc which welcome winning punters and don't chase them away at all.
I don't know why some people will just out of their own personal assumption made a conclusion on what is not it, why are they thinking that sportbooks are being manipulated by the providers, if this had been that easy or possible to achieve then why are sone gamblers still found winning over the house, or maybe we should ask why many gamblers are still interested in going after this while gambling.