Actually they didn't need rescuing at all since Asteroid M isn't even a "mutant concentration camp". Scott and Emma turned it into a safe haven for all mutants. Clint is just overreacting to what he's seeing on the news (the media is falsely reporting the facts, unintentionally however) and it's ironic a misunderstanding about how Utopia turned out caused him to make up his mind and go after Osborn directly.