I see a lot of developers complaining about this, but from the point of view of a user, that feels like the limit of how much users (me) would be willing to read per-app.

In my experience, it's rare that an app cannot be adequately described in that space.

Your comment contains 257 characters. Do you seriously think adding 72 more would allow you to effectively describe an app of any significant complexity?

It's difficult, but it's mostly doable, and more importantly, necessary. People don't read, and even if you had a longer description people aren't going to read more than a few lines of it. So instead of losing out because people didn't read the whole of your description, I see this as an incentive to place everything within the region people will read.

However, I do agree that with apps of increasing complexity (WaveSecure comes to mind), you'll have to leave out a lot to fit in the space. In these cases though, I feel the rating and comments should give the user enough push to try the app, after which your app can describe itself all it wants.