The issue we were talking about was maintainability.

Giving links longer expirations is trivially easy, and I already do it in cases where it matters, like submit buttons on big forms.

The problem is that links expire at all. There are two products: HN with "link expired" and HN without "link expired". You can write the former in a highly maintainable way.

Also, even if you accept that links expire, it's not trivial to make the links not expire for a long time. You can add a lot of RAM to a single machine, but only up to a point. Supporting multiple machines is very hard, although it can be done (distributed object system). RAM is not the only problem however. The server is inevitably going to restart once in a while. Perhaps not in the literal sense of killing and restarting the mzscheme process if you're very careful, but still in the practical sense. The data structures for storing content change as you develop a web app/site, thereby invalidating old closures hanging around.

I get the same problem on Reddit, except they call it "there does not seem to be anything here".