Not really his fault
He made the site as a social network for his university. It got big for reasons outside of a trendy new site - the government saw it as an excellent tool of surveillance of citizens and heavily promoted it. Mark got super rich quick and was thrown into new territory he really wasn't familiar with.
He really was an awkward and innocent guy in the beginning years of the site. As far as ''who he is now'' that's just like a lot of men who's personalities changed during their careers. Mark got colder with time, power and more money - hardly a surprise. Still like him better than Musk.