If Oda wouldn't keep writing oh so bad and super evil activities celestial dragons do for basically no logical reason at all, I'd be full on supporter of the WG, probably including even Ohara.
Ends almost always justify the means.
But they do explicit evil stuff and are rather of the generic evil villain type. They are not interested in a normal functioning world government, no they want to commit mass murder for fun. That's the ridiculous part, not the WG or how they came to power a millennium ago.