It's hard to parse out the social media thing, because it has made everyone petty and insecure, and outraged, but the post does come off angry, and bitter, and resentful, which is not how you would expect someone on that level to behave, unless you know better, which I kinda do. People are just people.
The inability to take criticism, or receive it graciously is a major indicator of a lot of things, including, of course, deep insecurities. I have a jet and you don't, is right out of the sandbox playbook for children.