I know developers who can design and code. The contempt is earned as most "UX monkeys" can just sling photoshop and that's the end of it. Too costly in any startup. Too useless in anything else.

I'm a developer and I am happy to leave the UX to someone who knows what he/she is doing. That goes far beyond "slinging photoshop" however. When I'm using a website or application I can usually spot where a developer did the UX, because it's quirky, "clever," uses conventions different from other parts of the system, or worst case is completely incoherent.

Depends on the platform. I've come to despise mobile UX monkeys if they can't write Cocoa. Period.

On iOS it's different, the developer knows the best.