One of the frustrating things about gaming is the tendency not to release completed games, but instead to release a buggy, incomplete mess. The bugs gets fixed post launch (sometimes), and DLC is for "all the real content".

But, at least in my tiny corner of the world, I find friends saying "Oh, I'm not going to buy that game until all the DLC is out, so I can play the complete game. It's cheaper to pick it up all at once, too." So all the revenue the companies seem to be counting on to help them finish DLC etc. never comes. Most prominently, I know several friends who put off buying Civilization 6 until it was "really done".

I find it funny how games not being finished at launch has trained so many of my peers not to buy at launch.