Zardnaar
Legend
No, they don't. There are lots and lots of unlicensed CRPGs that have D&D style attributes: Dragon Age: Origins (EA), Fallout's SPECIAL system, World of Warcraft, Warhammer 40K (with a movie and TV deal in the works) and lots and lots of lots produced by smaller companies. Go on Steam and do a search for RPGs.
They have plenty of money to fight Hasbro, given that the video game adaptations would also be effected.
WotC can't afford to loose. The reason they introduced the OGL in the first place was because there was uncertainty about what was and was not WotC's intellectual property. And they wanted to avoid having to test it in court. Not only would that have been expensive, the chances are they would win on some points and loose on others. But either way, it's outside their control. The OGL was a way to try and gain control, but it only worked so long as people were willing to abide by it.
But WotC's problem now is that one of the big companies, like EA, Microsoft or Apple could beat them to the punch with a popular D&D-clone VTT or MMO. I'm afraid Solasta has proved that is possible and legal under the current OGL, and that is probably what has the lawyers spooked. It didn't matter when D&D was a minor thing, but with it's increasing popularity, there is a very real threat that a bigger fish than WotC might use the OGL to try and steel D&D out from under their nose. It's unfortunate that WotC's attempts to defend itself could lead to a return to the Wild West conditions of the 70s and 80s.
I've played a few of them. Their systems are different enough to hold up in court.
PF2 and Level Up ability score system are lifted directly from 3.0. No OGL that's potentially WotC intellectual property.
If WotC gets nasty you're looking at court battles over every book.
You could probably rewrite your books but if WotC wins (note IF) anything in any of their books is concievably off limits.