Mojo complains about new characters muddying up the water and eclipsing classic heroes, despite the fact that the old characters are still there and past exploits are unaffected by any new character introductions. Ironically, two of the visual representations of this complaint are Quentin Quire and Doop, two huge favorites in the X-Men fan community and characters who have been backup players to Wolverine, an X-Man who, even in death, is in more books than either Quire or Doop combined.
To be fair, not every little snipe is unwarranted. Mojo notices on his cell phone that viewership ratings have dipped. He wonders if perhaps killing off a character will boost them. This is definitely commenting on how cheap superhero deaths often are, and how they can feel like nothing more than a sales tactic instead of a natural story beat.
The real meat of this issue is the way in which Mojo grapples with the outside world, something that can be hard to do when your head's buried so deep in the exploits of fictional characters that it engulfs your life and your better judgement. And in a very sly manner, Aukerman and company sort of let slip the answer to ending this whole debacle in the comic book community: Not everything has to go the way you want in order for you to be happy.
Cycles come and go in pop culture. Comic books are no different. What was once the norm erodes over time. Either adapt, or live in the past. The choice is yours. Fighting on the internet over it isn't doing anyone any good.
Luckily, it seems most fans are just trying to find works of art to gravitate toward and stories they can relate to on a personal level (what more can you ask for, really?). If goofy, vaguely apolitical ‘90s comics with gory violence and eXtreme™ artwork is what you dig, bully for you; comics like that are still being made, just not at the level they once were.
If you want to see characters who represent your race, gender, ethnicity or social upbringing, then there is nothing wrong with that. If you can’t relate to Riri Williams on a personal level, then no one is forcing you to read the comics she’s in, but it’s not fair to begrudge readers who do enjoy them. Period. Mojo understands that. But can everyone else?