Yeah, if a DLC isnt just content taken out of the main game (in a way that makes the main game worse) and is reasonably priced for the amount of content it contains, then it is a good way for developers to get paid for continuing development of a game after launch when it was already finished at launch.
The Witcher 3 DLCs for example were pretty good.
I got it recently, so after a lot of bugfixing.
While I did encounter some small bugs, it really wasnt anything bad. Performance still isnt great, but it is playable and the game does look pretty good.
While the gameplay loop really isnt anything new, I think it was worth the 30€ I paid for it.
But, of course, it would have been much better if they would have released the game in the state it is now, both for us and for them and their image.