Ooh, an interesting one. Maybe Garth Ennis wouldn't have such a chip on his shoulder about superhero comics. 😆
TYVM.
Well, how could we make them less niche?
Whew, excellent question. You'd need stories (or writers) able to tie them into the broader Marvel Universe, & writers on other books willing to cross over into a "ghetto" book (of sorts).
I've wondered if the whole mutants idea doesn't make X-Men a kind of self-imposed "subuniverse" by default, which may not be amenable to broader inclusion. Unless you can sell Marvel's writing staff more generally on something like the Registration Act concept, or *Civil War as more than a miniseries or sales gimmick. (You'd also need to do it before the book goes into reprints, & probably before its sales go off a cliff, or it's going to look like exactly that: a sales gimmick.)
IDK how you'd arrange it, but I liked the
Avengers storyline that sent them back to the *Old West, allowing tie-ins with Marvel's Western books. Maybe that could work? (I'm not sure that helps sales, seeing Westerns were on their way out, too...which might be the only reason for the tie-in to begin with.
)