On the one hand I agree that too many series are milked for money long past the point of sensible content. On the other hand:

Many writers/studios attempt to continue creating content after the “big bad” is defeated but interest doesn’t continue for many. Take Harry Potter for instance; the reader is told that Voldemort is a terrible villain and unless he’s stopped, all is lost. In the end, he’s beaten and the good guys win. That’s it. You really can’t do anything afterward because there’s nothing else left to accomplish.

Harry Potter, Star Wars, LOTR, etc. all have something great in common: World building. It's really a shame to let these worlds go to waste. I think that D&D does this best - various authors writing different characters who have different adventures, where one specific story doesn't need to be the end of it all. Other bad guys can crop up, other evils need to be defeated, and there's always a new adventure waiting to start. The worlds where the author pulls the "what if they had kids" move like Harry Potter or Naruto feel contrived and hollow, but even this can be done right to an extent - the switch from Dragon Ball to DBZ showcased the idea of productive timeskips. It brought new characters, new content, changing circumstances without disregarding old canon, revitalized old (previously minor) characters, and didn't lose sight of what made the original fun.

I suppose really the question is: Is the writer truly committed to this continuation, or is it just a cash-grab by a greedy studio/a fanfic from some new writer looking to impose their own ideas on a pre-existing work? Authentic dedication seems to be what's lacking.