Regardless, if that level of deep thought was actually put into the psychological profiles of the characters of this show, I'd think the writing would be far more intelligent than it generally is

That level of thought was actually put into this show, what you would think or not doesn't matter because well that's just your perception.

it's just not the stunning analysis of human psychology you seem to want to see in it

If it's not then why you don't provide any counterargumentation to his analysis? Saying it's not without saying anything supporting it is pointless and doesn't do anything besides showing that you're bad at discussions.

The show has literally never said a single thing that hasn't been said dozens of times in other media.

So do most works that aren't "Thus spoke Zarathustra" and similar. Writers usually convey ideas and concepts that scientists, sociologists and philosophers described first but they do that in artistic manner to teach, bring these concepts closer to the people and such. And even if someone comes up with something "entirely" unique it's mostly just taking existing ideas from different perspective or adding something to them.

Weird, plenty of other drama/comedies have surprised me with their stories and characters. Bojack almost never has.

And that's entirely subjective thing that doesn't tell anything about objective quality of work.

Maybe show me an academic essay that analyzes the actual full spectrum of television and concludes Bojack somehow stands atop all shows ever made on the shining pedastle of "the realest depiction of mental illness in all of television

Academic essays are great and all but that sounds like appeal to authority. When authority (in this case academy) says something it isn't automatically good/true/whatever and when non-authority says something it doesn't mean its value is lesser. Therefore in any discussion you deal with what is said not who or what says that and where.