As stewards of the hobby they put 5e, which they spent a great deal of time and money developing, into Creative Commons, which is pretty remarkable. Making the SRD public back with 3e was pretty remarkable.
As I posted previously, I feel like there is a lot of conflation of D&D with 5e or, in this case, "the hobby," which is being used to pillory WotC for protecting their control over D&D. In fact, I feel that there is a huge double standard - WotC has gone much further than most companies ever do in sharing access to their IP, and yet it seems like it is never enough, like some folks expect them to just put D&D into the CC.
They might be partial "stewards of the hobby" - that's debatable. They are the owners of Dungeons and Dragons.