Because the author is delusional and thinks people actually give a shit about their "top tier" company...which most likely just sold ads on the internet.
My comment was mostly in regards to the snobbiness of the "top tier" aspect. The person is free to explain his decision to leaving a job of course, but the bragging is just sad.
I think that's fair. Either way people don't need to be so unnecessarily harsh. It was pretty clear OP didn't intend anything particularly harmful. It was probably just naivety or a lack of self-awareness...but people are talking in here about it as if it were pure evil.
Is this person not allowed to put his own thoughts down on his own personal website? It's not like he's getting on CNN and preaching.