Sorry, but I just can't get behind the justification for Shaw's idiotic plan in X-Men: First Class. Yes, I get your point that this is a throwback to villains from spy movies in the 60s but that's not an excuse in my mind because of the motivation. Those villains WERE out to destroy the world. Shaw is not. He believes this will create a mutant utopia and that's where it falls apart.
If Vaughn wanted to do a throwback to spy villains who wanted to destroy the world, then why not use Apocalypse? That way, he'd have motivation that actually fits with his plan -- he wants to engineer a world where only the strong will survive. And a post-apocalyptic wasteland is just the kind of world he longs to live in.