Vote to save / win means HMs can pretty much act how they want and are more likely to stay in/ win rather than the bores and radar dodgers.
In the past a controversial/ game playing/ non-nicey wicey HM would have been evicted or lost (Rex, Victor, Makosi, Adele) or even ejected (Nick) it is now possible for these HMs to survive and in Aaron's case...win. If you hate someone like Aaron then you have to vote for whoever he's up against eg Tashie in week 1 or Heaven in week 3 but she may annoy you too, hence Aaron stays as his fans vote to keep him. Tashie and co don't really have a fan base. The more times Aaron is kept in the more his fan base is affirmed. So haters can't really kick him out, all they can do is boo