> - do not greet; we don't have time for that bullshit
and
> do not abbreviate words (you have abbreviated "you" as "u"); if you do not have time to type the words, we do not have time to read them
So they have apparently enough time to read full words, it seems!
With “u”, I have to pause for a moment and think “that’s not a normal word; I wonder if they meant to type ‘i’ instead (and just hit a little left of target)?” and then maybe read the passage twice to see which is more likely.
I don’t think it’s quite as much a contradiction. (It still could be more gruff than needed.)
edit: I remember how some communities changed into: The help isn't good enough, you should help harder, I want you to help me by these conventions. Then they leave after getting their answer and no one has seen them ever again rather than join the help desk.