Because you're attacking an HN regular for trying and failing, when he already admits he has a lot to learn (and failing teaches you a lot) and just wants to make something useful for people. It's not kind to attack people for failing and goes against the HN ethos, because the only real failures are those who were too timid to ever try.

I understand you were replying to someone else's comment, not any claim Jason made. You may wish to explore ways to be more diplomatic, or hold back the attacks if you can't find a better way to express yourself.