User blog comment:Neowitch/Why not just ask nicely?/@comment-1595565-20140724221255

First, you must ask yourself what kind of rulers the Donquixotes were. They could have been maniacal tyrants for all we know, not that anyone is alive now who remembers it anyway. Second, as we saw with Crocodile, the Marines and WG don't take kindly to a Shichibukai getting involved in the internal affairs of another country, especially if the affairs are of the rebellious persuasion. Doflamingo threw away his birthright, so the world noble card was out. People liked the Riku family and Dold wasn't about to just hand over his throne to a pirate. Even if he outright threatened Riku, he couldn't win over his subjects and then he would be the puppet, rather than the puppet master. His plan, in one night, accomplished three things:

1. It took the Riku family out of power.

2. It established a justification for his presence in Dressrosa, and with such great timing. AS it turns out, he was in the neighborhood the night the king and his friends decided to go postal. And, being the badass hero gentleman he is, put a stop to it.

3. He made the citizens go from supporting Dold to supporting him.

Being the beloved savior of Dressrosa solidified a place for him and his boys in the hearts of the people. He made himself the hero of his own story, this time deluding the people into thinking he was the hero, rather than himself, like his namesake, for which I refer you to the real world piece of literature bearing his family's name. I suppose the easy answer would be to call him a sadistic sociopath and leave it at that, but I have invested too much time and effort into analyzing him to simply leave it at that.