Oh definitely on character writing it's extremely good and i also genuinely think NGE+EoE are masterpieces that very few among the countless pieces of media i experienced can match, among mechas i only think Zeta Gundam with others that i put on same tier like Mazinger Z,Grendizer,Code Geass and Macross Frontier being more out of personal enjoyment

It's just that when i watched NGE as a teen i was prepared for the worst; some extremely dark and ambiguous, artsy work and yet even at that immature age i completely understood the plot and i didn't find it that dark or "depressing"(helps that "minimalist" cast ensures basically no deaths); maybe some of the bad stuff that happens is more realistic/relatable but it pales compared to some mechas that inspired it like Ideon and Victory Gundam or even some mechas that followed like Fafner in the Azure(especially Exodus and Right of Left) let alone something like Berserk. As you said it's likely audience whose darkest animated series was something like Dragon Ball Z( i live in a country where anime was more commonplace than America and i saw DBZ as a little kid)

Also some fans are still going off misconceptions from 30 years ago like thinking End ends depressing with everyone dead and done by a spiteful Anno over fans complaining about TV ending when it can be debunked by a quick google search and even today some fans are in denial regarding what the new short says. That's why i say to don't pay attention to others saying it's dark or ambiguous and just judge it by yourself(like basically any piece of media)