alt Hacker News> supports a gigantic predatory underage gambling market
Last year Valve updated their code of conduct and effectively banned gambling. They've also been known to send cease-and-desist orders to various CS:GO gambling sites.
So I wouldn't say that they support it, though for much time they weren't actively combating it either.
The above commenter was probably inspired by the recent investigative(!) video series by Coffeezilla (and decided not to mention it?). It was either in part 2 or 3, where C-z alleged/suspected Valve's legal actions to have been mostly about good PR and to send a signal to those ~websites~ businesses to keep them in check.
However it is indeed the case, that Valve has introduced greater and greater restrictions on inventory handling. The measures obviously go far beyond just counteracting possible scammers and phishing. Still, I am inclined to believe, they could've implemented all these features many years ago, if only they had wanted to. I highly recommend the videos. You can maybe skip the first one. It's mostly about casino owners' drama.
[1]: https://www.youtube.com/watch?v=q58dLWjRTBE
[2]: https://www.youtube.com/watch?v=v6jhjjVy5Ls
[3]: https://www.youtube.com/watch?v=13eiDhuvM6Y