I would pay full price for Fallout 3, New Vegas, Oblivion if they would simply fix the bugs and re-release them to run properly on modern systems. (And I'm one penny pinching MF)
I would guess they don't do this because they're worried the community will freak out about the update breaking mod compatibility but they already kinda did this with Skyrim when they released the Enhanced edition or whatever they called it.
There has to be money on the table here for them. If modders can fix their games without access to the source code then it couldn't be that labor intensive to hire someone to go through the code and fix it right?
I just don't get it. Are they maybe worried the old games will cannibalize the audience for their new games or something?
I shouldn't have to beg these assholes to be greedy. This is America god dammit. 
It's 100% cost savings on Bethesda's part. I remember hearing about bugs in Fallout 76 that had been in the engine since Morrowind that would normally be handled by a community bugfix patch.
And they require such extensive modding to be playable that it just feels pointless to me to even bother. And it's such a pain in the ass too - oh, you need mods from Nexus, but you also need this other thing, oh and you have to run all these extra programs to make sure they don't explode.
These games are not fun enough to bother with all that nonsense.
This so much. If it was one uniform process I wouldn't complain so much but it is a dictionary definition shit show. And fuck Nexus for making me register.