Not necessarily, but good developers need to be thinking about their upstreams and downstreams. This is often uncomfortable because a developer personality often wants to know all the minute details and not have to worry about areas outside their core competence, but you can't build large scale software without at least a critical mass of developers thinking big picture. UX in particular depends on the task at hand, but if it's a consumer product and you're working fairly close to the surface (client or API tier) then yeah I'd expect some awareness of UX.