I think they are playing a longer game, knowing a younger generation of gamers are likely to see it as normal as they haven't the experience of the time before. But there is no way they are walking away from that huge cash opportunity. It's an amazing thing as well, a ready built market, a product you have no costs to create. Just skim a little fee (like steam does with games) and you have basically free money.
I mean It's not even just mods that add something either, taking place of DLC. But all the bug fixes, you end up with a profitable bug fixing solution, which means they can slash their own costs in favour of letting the "mod community" fix all the issues.
It's shocking they haven't been far more forceful with it when you consider the greed and easy money situation. But I really think they will eventually.
(the one hope is that Microsoft is involved, and they have a habit of fucking things up a lot of the time)