Agreed, however, if Steve Englehart was able to juggle SEVEN different GLs in the post-Crisis era without any problems, I don't see why a good creator can't juggle SIX.
As others have said, the main problem, it seems to me, stems from the fact that the creative energy of the GL franchise has never recovered from the one-two punch of the movie flopping and Johns ending his run. For better or worse, Johns was a tireless workhorse coming up with new concepts and characters while simultaneously reinventing old ideas into something exciting.
What has been done since Johns left? The Durlans framed the Corps. Mogo became the new Oa. Hal got a really crappy new costume. Guy briefly experimented with a ridiculous porn-stach that made his bowl-cut look stylish, Kyle got super-Catholic for about a minute and John became leader of the Corps.
Compare that with the onslaught of new ideas and characters the GL franchise produced during the Johns/Tomasi era, it's no wonder that fans are feeling unsatisfied.
Granted, every franchise goes through this period of stagnation and creative rut for a time. I can't even remember what was going on with Aquaman following Peter David's run. Superman's certainly had his low points. The pre-Morrison Batman was just awful, as was the post-Johns JSA. The post-Waid/Johns era of The Flash was truly abysmal. Wasn't Bart aged up and made The Flash for a few minutes there? I think it was so awful I scrubbed it from my memory.
I suppose it could be worse, we could be in the same boat as Young Justice, Justice Society and Legion of the Superheroes fans
At least we still get four generally well-done GL comics a month, even if they aren't particularly memorable. They are at least fun to read. I am looking forward to seeing how the Zod vs. the GLCorps turns out, but that is hardly based upon character progression. It's just mindless spectacle. There's no expansion or exploration of the ideas surrounding Green Lantern being played with. Feels like empty calories.