I don't think it necessarily has to be bad. The Flash was a good enough show and for what was produced, had a very low budget. Word is it cost $50M to make a season of the show.

TV shows should be episodic and not just a movie split into 8 little parts. Refocusing TV shows like this allow you to reduce your casting costs because you can sit with a smaller central cast of characters. Flash was rather unique because the villain was mostly an "unknown entity thing" that rarely ever required an actual actor.

John Stewart can have some fairly cheap CGI animations compared to the others. Stewart was most known for using a green fist or green hammer. That could save a lot of money compared to Alan Scott or Hal Jordan who used a lot of.... creative constructs.

They can also save money by restricting a lot of the conflicts to Earth. Paralax comes to Earth and starts infecting super villains that Green Lantern has to stop? And then the final episode can involve his wife getting infected and having to choose between killing his wife or letting Paralax live? Sure, great show.