Big things often start small. In fact, usually start small.
And in any case it's just mean of you to piss all over these guys' efforts. It makes me embarrassed for HN when people launch something new, and this is the sort of response they get.
It saddens me that the most common response these days seems to be some version of 'Let me list all the reasons why this is crap.'
What happened?
Now that the population has grown, there are more commenters and more Show HNs, yet the presentation hasn't changed to accommodate this (same number of posts per page, same comment layout despite more comments, etc).
Maybe something like "Review HN"? Whatever it would be, it may be time to get more specific. Ultimately you're trying to filter out unhelpful comments. Those will always appear, but now there's just more of them in the same space...
I agree assisting people to reach the airport on-time may morph into a larger corporate vision, but I disagree it's likely to contribute to solving cancer, making better fuel, or reaching strong AI. ...And it's arguably a distraction of rare talent from that calibre of problem.
Conversely, a startup that grows sufficiently big can contribute to the solution of almost any problem, including those you mention.