"It was at the top of my list of anime to watch this season in a tie with Asobi asobase and some people ranked it even higher than Asobi asobase due to superior drawing and animations."
"you're projecting the idea that it's a show just on average and a filler when it's actually one of the best that aired this time, it's just that it's not a battle manga or any of the other archetypes."

It's my opinionated review of the show. If the show is something you are passionate about liking, it's natural to be in disagreement about any perspective that contradicts your interests. Does it matter if the show is someone else's top of the list or not great on someone else's review? or if the consensus of the mainstream says it great or not? If I were to make a review, I am going to make a review based on what I honestly think about it.

If there is anything I forgot about mentioning in the review why this show hooked me into finishing it, it has one of the best soundtracks I've listened to and for the sake of watching it full before making a review.

"You must NOT like comedy like at all... I mean, Grand blue is damn HILARIOUS"

I did enjoy Arakawa under the Bridge, Chromartie High and School Rumble. Humor is subjective.
I like the show.

"Try to judge it like that instead of focusing on the diving, because the show itself doesn't focus much on the diving either."

I did and I stuck with my set criteria.One can execute comedy without sacrificing the plot and explore more character development for the supporting characters, one example is School Rumble. The show revolves around a love triangle but viewers are able to see the story in multiple perspectives that let the supporting character shine through episodes. On the other hand, the characters on Grand Blue hardly get any meaningful exposure.

We get hints that Chisa works at the aquarium and loves the ocean but we don't get to see scenes that she has her own moments away from the shenanigans the MC is involved into. We get some laughs about Nananka's obsession with Chisa but no further explanation on how things came to be, we are left to accept what is. If the argument is about the collective experience as a group, then the anime falls short even on that department. There less room for individuality to grow if most of the scenes feature the characters lumped into one drinking session and less of the individual alone time to get to know them.

There are ways to create more depth in a character even if it's just a comedy anime and I guess my opinion about Grand Blue just doesn't suit it's mainstream fanbase even if I can agree on liking the show still.