In much the same way Brabham, Lotus, Williams, Ferrari and plenty of other cars were just better at the time. The FIA have always stepped in after a couple of seasons to even things up. Mercedes had 8 years of unchecked dominance. It doesn't diminish Hamilton's achievements but you have to acknowledge the FIA's inaction allowed him a virtually free run at a few of those titles.
Sorry but I don't have to acknowledge that, because it is not correct.