Doubt my bro had She Hulk comics or else I would had knew about it. Or maybe he did but I dont remember it. He stopped buying them in probably about 1985 or so. He focused on the core Marvel IPs everyone knows like Avengers and West Coast Avengers, Spidey, Cap America, F4 etc... Dont think he ever bought DC comics. I dont remember any, plus he always said DC stood for Dumb Comics! I think his last or one of his last comics was the first Punisher set which had a typo on the cover..... something about saying it was 4 issues but was really 5. Or it said 5 issues but was really 4. Something like that. I remember he liked a comic named Longshot.
Googling it, it doesn't seem like She Hulk was very popular at all though.
https://screenrant.com/she-hulk-marvel-comics-popularity-problem/
As for Morbius and Madame Web youre right. Those werent Disney. There's so many superhero movies hard to keep track. But googling it now, the Phase 5 movies in this list are all Disney.
https://en.wikipedia.org/wiki/List_of_Marvel_Cinematic_Universe_films#Release
And similar to Pixar movies they are trending down in money and review scores.
As for GOTG being popular despite being a new comic, who knows. Maybe they took a chance on a motley crew new to people, instead of characters that werent very popular to begin with despite being around (similar to Sonys Morbius and Madame Web, or whomever made Kraven). If they arent popular known characters for comic fans, why bother making a big TV or movie out of it.
You're assuming comic book sales A) "prove" the subjective quality of the title and B) will translate accurately to movie box office results.
By that argument, Aquaman would be the highest selling DC comic (and it isn't) since his first movie was the highest grossing film of the DCEU.
Regardless, John Byrne's She-Hulk run is still widely talked among comic book fans today as easily one of Byrne's best works (and it started in the late 80's, so your brother wouldn't know about it if he stopped in '85). And 60 issues is hardly a short run for a character who isn't one of the highest A-listers. And clearly there must be some demand for her runs because most of them have been reprinted in hardcover omnibuses. Marvel Comics doesn't invest in omnibuses unless there's demand for them. In fact, they do frequent polls to gauge interest on what fans want to be released in omnibuses. Sometimes runs don't do well initially but gain a following over time, especially with digital reading now an option it allows word of mouth to build on older runs with a cult following.
I also know one should double check sources claiming any particular run is "cancelled". Often a writer just wants to move on, very few want to stay on the same title for super long (Chris Claremont writing X-men, Marv Wolfman writing Teen Titans, and Geoff Johns writing Green Lantern for hundreds of issues is an exception, not the rule), and especially nowadays they will reset the issue number once the run ends and a new writer comes on afterwards. So in cases like that, the run wasn't cancelled, the writer just simply moved on and a new one came on later, yet most casual people who don't bother looking into it just see a number reset and the previous writer left and go, "oh, guess it was cancelled."
Also, if you look into it, Peter David's run of She-Hulk was sabotaged by editorial error. Peter was not informed that the character would be utilized in the main Hulk book written by Jeph Loeb, and that book was making it so her character arc in David's run didn't make sense, thus readers saw no reason to pick up the She-Hulk book due to the character being confusingly different between the two runs. Had editorial done its job, informed both Peter and Loeb about what was going on in both titles and thus able to coordinate better, the book probably would have lasted longer.
Limiting adaptations to only the most iconic characters would suck shit. There's a wealth of great stories and characters that people could discover if they gave it a chance. Guardians of the Galaxy proved that. For example, when the X-men join the MCU, I really hope we get X-Factor (based on Peter David's run) and X-Statix as they're well-written and unique characters and stories, rather than just catering solely to the casual "but why aren't Logan, Cyclops, Storm, and Beast on this team?" crowd.
Also, all your link proves to me is that I will never take CinemaScore, whatever that is, seriously. This is coming from one of the biggest MCU fans here: EVERT FILM in Phase 1-3 are at least an A?
Incredible Hulk? Iron Man 2? Thor 2? Ant-man 2? Captain Marvel? These all deserve an A? I don't even full on hate any of these, but come on now.
Also, kind of worthless to only provide the critic scores from Rotten Tomatoes but not the audience score. For example, the audience score for Captain America: Brave New World was quite higher (77%) than the critic score (48%) for it.
www.hollywoodreporter.com
