A sign of this is not loving other people's work. People who love to write, but not to read, produce dreck.
There are lots of people who love to program. But how many people love to read really good source code, or learn from books that teach difficult concepts in programming?
Great question, I'd like to know too. Sometimes I poke around popular open source projects, like the rails source. Here's how they implemented the syntatic sugar for things like "1.month.from_now":
I recently found http://refactormycode.com/ and it looks interesting for learning, though not comprehensive. Sometimes it's nice to see the "before and after".
Actually, I'm not sure if this is true. I recently watched a lecture (that I can't find right now) on something like "How to write a good math paper". In it, the speaker made what I thought was a wonderful observation:
Often, he sees new graduate students reviewing paper submissions to conferences or journals. These students are usually very critical, and their criticism is usually dead on-- the things they complain about are genuine defects of the papers. However, when those same students write papers they do not live up to the standards that they have set!
So, the problem may be more of what Ira Glass hints at-- people who have good taste, but are unable to apply that taste fairly to their own work.