The people arguing are all idiots. Let the author cook, because none of you are the one with the years-long multi-series franchise. You cannot judge a meal while it is being prepared, only when it is completed.
I think you're being needlessly harsh, and you are absolutely using multiple argumentational fallacies.
One can judge a work of art without bieng able to make it. I can't play guitar very well, but I can say with confidence that Zak Wylde is a hack, and Kerry King can't play a solo to save his live.
I can absolutely judge a meal before it's been cooked. If someone poops in the soup, it's not gonna be good.
You can't make blanket statements like this without being wrong.
And the fact that it's long doesn't say anything about the quality. The fact that it's this long and is still internally-consistent says something about the dedication put into its creation. The art keeps getting better. The story gets deeper and richer with time.
These matter.
CoD is a long-running series of video games, and they're all the fucking same, and matter less and less with time.
Mötorhead was going for decades and dropped in quality very briefly for a couple albums, but is otherwise consistently awesome.
The manga is good, the author plans carefully, patience is a virtue.
These are sound arguments.
"You didn't make it, and it's not done, so criticism is invalid" is so... incorrect.