At the end of the deal when the casinos work hard and make a name for themselves it is much easier to add sportsbook and create some sort of safe bubble. When a new sportsbook comes out I wouldn't know if I could trust them or not, I would have no idea what to do, however at the end of the day if a great casino like fortunejack/stake/mintdice adds sportsbook then at least I know there is a trust going on there, for example mintdice is a platform that I love and trust, so why would I risk playing somewhere else.
Sportsbook or not, it does not a serious matter. The truly serious matter is gambling is risky itself, and much more risky than trading or investing. You can hesitate to invest or trade but sometimes when a gambler falls in love with one game or more seriously get addicted with that game, that gambler will more easily to spend money to gamble. Uncontroled gambling mostly will cause broken-capital for gamblers.
I would prefer to use gambling, and sportbooks from old and reputable casinos, and most important thing is I don't spend too much money to gamble because I don't prepare for my serious losses with gamble. Gamble for fun and to relax and refresh my mind after long time of trading.