Nowadays, it has become pervasive on social media, and lost value as everyone uses it. It acts as a rhetorical device which can disguise the poor quality of of the argument.
So I agree with your last statement. Snark to me implies a wit or cleverness as well as defiance and challenge. This is why it worked for Dijkstra. The brevity of the messages above are just a show of a lack of ability or desire to communicate and clearly express an idea. The above are just unnecessarily verbally abusive. They incite a negative response before the person even has had a chance to process other meanings of the message.
Brevity is a virtue; and Golang has very little of it.