The most obvious and worst one is writing bad code and not wanting to learn to write properly. Those people can't even be called developers.
In general, not craving knowledge is a bad thing when it comes to software. Developers need to get in touch with new tools/technologies or need to become masters of the technologies/tools they already know. Not doing one or the other is a surefire way to drag oneself (and one's team) down, if it doesn't become a way to get oneself replaced.
Another one is bad communication. I'd rather not work with developers who can't make themselves clear in their output (code, comments, documentation, specifications, requirements, opinions, etc), or that are unwilling to read/listen to my input.