That's not being pretentious, that's being blunt. I personally as a dev, appreciate that.
If you think the code can be improved you should say that, and exactly why that's the case.
When you're mistaken you should be able to take the criticism.
Your mission as a dev is to write the ideal code, and being overly polite can stand in the way of that.
Yes, he's a genius but I kept thinking "damn, the ego on this guy" while reading that.
I love Linux, and thus, I love Linus... But he has a very large ego, there's nothing wrong in pointing out reality. That's just who he is. At least his ego matches his skill, which is something rare. He deserves to be cocky, he earned it.
You'll get downvoted here because most programmers have elevated egos and think this is normal behavior.