IMO this is not a problem of maturity, this is merely a direct response to the integrity of the greedy.
The coder released a program out of good will, yet received nothing but insult, what's the point?
If the "comments" have anything that is constructive or at the very least a single meaningful message, one could argue that the coder was being immature.
But in this case, the feedbacks were given by the degenerate of the society who deserves nothing, nothing is exactly what the coder gave them.