IMO, the bulk of the vitriol comes from two issues (not that I think much of it is sound):
- Multiple claims of outright dishonest behavior and undue credit-taking entitlement from his co-founders (even prior to the lawsuits)
- His extremely privileged background. Given his family's political connections, wealth, ivy-league legacy, and prep-school pedigree, he risked very little (compared to most entrepreneurs) when giving a pre-undergrad start-up a go.