DC has Batman being called upon by the Gotham, while the human population fears and hates Marvel’s mutants for being different.
This resonated for outsiders, both adolescents and adults, who have ever felt isolated because of their uniqueness or differences.
What hardcore Marvel fans love so much about the characters is how utterly flawed they are.
While the DC world is usually pretty shiny and perfect, Marvel features heroes and villains who are often making mistakes, or who are under-appreciated by the outside world.