First of all, they have love affairs with humans/other gods! A real divinity wouldn't do these adulterous things! This is not good! I...I... really don't have anything else.
Secondly, they act like children sometimes. For example, in the story of Arachne and Minerva, Arachne is winning the contest, so Minerva gets mad and tears apart Arachne's quilt. Also, some of the goddesses (*cough* Juno *cough*) become