Legacy heroes are nothing new. DC has practically built their whole universe around it when they revived a few of their Golden Age heroes as new Silver Age versions with new names, looks, and in some case, powers. Marvel hasn’t done it quite so often, but there have been a couple cases. The big problem with a legacy hero, where the superhero name can be passed along to a successor, is that sooner or later the original–or at least best known version of that character–returns and takes the mantle back. This can occur no matter how popular the new guy is, though the new guy may stick around for other reasons.
Dan Ketch, the Ghost Rider of the 90s, was not one of those new guys who got to stick around.
The X-Men were created for two primary reasons. One was because Stan Lee needed another superhero team and was feeling kind of lazy, so he threw up his hands and said, “You know what? They were just born that way!” The other was as a at-times heavy-handed anti-racism allegory. The year was 1963, and the Civil Rights Movement was heating things up across the country. Younger readers of comic books could be taught a lesson on tolerance, and comics were a good medium for that, so here were the X-Men, mutants who were feared and hated by non-mutants for the crime of being born different. But the X-Men were good and defended regular folks against the evil mutants of the world, in an attempt to prove that not all mutants were evil.
Even given the sliding scale of Marvel time, where everything outside Captain America and the Invaders’ exploits during World War II depicted in a Marvel Comic (barring the upcoming Secret Wars) has taken place over a roughly 12 year time period, the X-Men really suck at their task of promoting tolerance.