People like Chris Claremont

Uncanny X-Men, originally published as The X-Men, is an American comic book series published by Marvel Comics since 1963, and is the longest-running series in the X-Men comics franchise. It features a team of superheroes called the X-Men, a group of mutants with superhuman abilities led and taught by Professor X.

The title was created by Stan Lee and Jack Kirby, met with a lukewarm reception, and was eventually cancelled in 1970. Interest was rekindled with 1975's Giant-Size X-Men and the debut of a new, international team. Under the guidance of David Cockrum and Chris Claremont, whose 16-year stint began with August 1975's Uncanny X-Men #94, the series grew in popularity worldwide, eventually spawning a franchise with numerous spin-off "X-books", including New Mutants, X-Factor, Excalibur, X-Force, Generation X, other flagship titles like the simply titled X-Men (later New X-Men & X-Men Legacy), Astonishing X-Men, All-New X-Men, Amazing X-Men, Extraordinary X-Men and X-Men Gold.