Time Travel to reset a setting is a cheap way to maintain continuity, on that we agree.
I know the old settings have a lot of problems. I'd just rather see them retired rather than messed with because WotC believes (rightly, I suspect) that brand recognition will squeeze a few extra dollars out of folks.
But there's a reason why you liked the old settings, right? There is some special part of them that made you love them, play/run campaigns in them, and grow attached to them over the years. And, because the parts of the setting you loved weren't the bigoted parts, the parts of the setting that made you love them will still be there without all of the problematic stuff, like senile wizard jokes, offensively stupid dwarves, racist Romani stand-ins, and the other problematic parts of Dragonlance, Ravenloft, and the other older settings you loved.
And those parts of the settings can connect with younger audiences. And younger audiences won't tolerate those bigoted parts of the settings and also have other preferences about how to play the game that the setting could easily be adjusted to accommodate.
You're following me here, right?
So, there are parts of the settings newer players could like. I certainly don't like Dragonlance, but I admit to enjoying some of its content. If they got rid of the problematic stuff, made the setting not bound by the lore of dusty old novels my players won't give a crap about, and fixed the other parts of the setting I object to (the problematic behavior encouraged by certain races, for example), there's a chance WotC could win me and players/DMs like me over.
The setting gets updated so you don't have to do all the work of converting your old books, newer players get to enjoy a different version of the setting that you love, and WotC makes money off of the book. That's a win-win, is it not?
Or would you rather that newer players don't discover the parts of the setting that you loved and leave the setting to die in the past because you don't like the idea of newer players playing a different version of the setting than the one you fell in love with?
Because that's kind of what if breaks down to. Either the settings Weis and Hickman made die bound to the problematic content they put in it because you don't want the setting to change in ways you don't like, or they get revisions to update them to a modern audience and the possibility of renewed greatness.
Do you really choose the former? Because I know what I have chosen and will continue to choose for as long as I plan on playing D&D. I don't care if the settings I love now are changed in the future to suit a future "modern audience", because I already love my versions of Eberron, Exandria, and Spelljammer and that won't be ruined because someone else is playing it differently.