From what I've seen, there's one division between programmers that's hard to overcome. Some see it as a tool to get certain results for a job. Some of them are bad, some of them are lazy, but most of them are good enough to get to their objective.

Others see programming more as an art. They take care to make the code not only efficient but also elegant. They'll read up on new and interesting algorithms and incorporate them in novel ways. They might often be behind deadlines, but when they are, they create things like GNU Hurd that inspire a lot of interest and lead to interesting results, maybe even teach people a few things. Their code is interesting to read. They tend to write the libraries that the first group uses.

Both groups contribute a lot, but it's not easy to get them to understand that about each other.