I never read "you should follow me" as particularly rude, maybe a little self-important, but not full on rude. Once you start trying to get followers you've pretty much implanted yourself in the realm of self-importance.
It's pretty clever, but if I really wanted to explain why he's an idiot, wouldn't I use the convenient comments form directly under that without trying to do it in less than 140 characters?
I never understood why everybody copied that "you should follow me" rudeness of a line.
Not thinking too high about yourself is how you win people's goodwill.