The spending of that one or two minutes at integrating searchyc.com or google.com would come back 1000 fold over the life time of the site, and probably much more than 1000 fold, and if he's that busy he maybe should pass the torch to people that can fully concentrate on making HN, the best site of its kind right now even better.
I personally find it very hard to believe that the trade-off is as stark as is portrayed here, working on a site like this is not in 'absolutes' like that, you simply do stuff because it has to be done. If a YC funded start-up would display that attitude to their users they wouldn't stand much a chance, in fact it is exactly opposite to what Paul says in other places to how one should deal with users.
It seems more like a stubborn 'I'll do this my way' kind of thing, Paul has kept the door solidly locked to others contributing to HN, but then goes and makes a big case about how he has only so much time to spend. It's hard to be arguing both of those at the same time.
Anecdotally, I've used search 100's of times to find a comment or an article that I'm pretty sure I read on HN but at the time didn't have an application for so I didn't bookmark it. This happens all too often in the tech sector, after all you can't know in advance which technology will land on your plate 3 months from now.