First of all, did you read Claremont's run? It was constantly evolving and changing. There was forward momentum. Characters got older, learned, moved on. It's the post-Claremont writers that have a problem with empty nostalgia and trying to regurgitate old stories ad infinitum(with decreasing returns).
Furthermore, it is one thing to try to downplay Claremont's significance to the franchise, but it is quite another to suggest that anyone else would have done the same or better. That is completely rude and insane. Where are all the other best selling 17 year runs in comics, then? Past or present? Claremont's achievement is singular and worthy of praise.
Certainly the market has changed, the medium no longer fosters such intimate, drawn out storytelling outside of more creator-owned properties(such as The Walking Dead spearheaded consistently by Robert Kirkman), but what was, was. Claremont's work still represents the best of the franchise, and the MCU would be wise to mine what the Fox-Men films largely overlooked in their ignorance and hubris.