Fair point. However, there are a bunch of complex laws in the US around gambling and gambling as a business is often banned where doing the same things as individuals is more often legal. Old but interesting:
http://fortune.com/2011/02/15/was-my-sports-bet-legal/Which I think get's into the same incentives as these games. If the house get's a cut of from poker players without risks they have reason to promote addiction. On the other hand friends playing for bubble gum can enjoy betting without meaningful downsides.
I don't think their are clear cut answers, but special regulations for companies due to the nature of capitalism has precedent in the US.