I think it's an affectation more than anything else. For an educated person typing on devices with, at a minimum, autocorrect for capitalization, I think it has to be a conscious choice. The worst part of me says it is ego/arrogance played off as a casualness or being beyond triviality.
> typing on devices with, at a minimum, autocorrect for capitalization,
posting from a windows laptop and Firefox, i get no autocorrect for grammar like capitalization. only firefox was detected as a work that needed to be capitalized.
That makes it even worse. So well-known and so much responsibility, yet so little care. If he can't even be professional when tweeting, why should we trust him with more? Probably good he's gone.