Ideally the license could be a bit less far reaching as well. Like if I post on D&D Beyond I obviously want my crap to be shared on D&D Beyond, but not shared for only god knows what else, i'm not really on board with that.
(Personifying this to demonstrate the logic. Not actually about any of the named persons.)
Frogreaver? I don't know how to tell you this... your stuff isn't that special. S'okay, neither is mine.
There are tens and hundreds of thousands of us, and vast amounts of overlap. You, and I, and Another Guy? Our stuff is all pretty much the same. We have very similar ideas. And folks at WotC have the same ideas, independently, just as you, and I, and Another Guy did. They didn't steal it, it was just frelling obvious stuff.
But, since we did post it, we have this weird idea that they
couldn't have had that same idea that you, and I, and Another Guy had. They
must have stolen it from you. Never mind that I had it, and Another Guy had that idea, too. But WotC stole it from you. So you sue.
There is far more risk of someone like us suing WotC over the perception of theft, than our losing out because WotC published our ideas. That's the purpose of the terms.