Ignoring the lack of updates if the game is buggy, games back then were also more focused on quality and make gamers replay the game with unlockable features based on skills, not money. I can't count the number of times I played Metal Gear Solid games over and over to unlock new features playing the hardest difficulty and with handicap features, and also to find Easter eggs. Speaking of Easter eggs, you'd lose a number of hours exploring every nook and cranny finding them!
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.
Oh man, while I was reading the first part of your comment I was thinking of the Witcher 3 DLCs the whole time, I'm so glad that you mentioned them at the end there!