First off: I love being a UX designer. It’s immensely satisfying to take a complex, potentially difficult experience and turn it into something simple and painless (if not downright delightful). But oh yes, there are a few downsides.

On the job:

• Every good idea you have to improve the user experience will require more work from developers. In my first UX job, I dealt with this by rolling up my sleeves and doing the front-end coding myself. In hindsight, this was not an efficient solution and it encouraged some misconceptions in my employer’s mind (generally, designer ≠ developer).
  
  Now I try to bring developers into the design process as earlier so that they have a voice in it (if they’re so inclined), understand the design rationale, and feel more ownership of the user experience. How well does this work? It depends on how user-focused the developers are and how much leverage you have with the dev team. Sometimes there’s a fruitful, enthusiastic collaboration—some developers are awesome and tirelessly dedicated to getting it right. Other times you wind up making a crabby developer miss his tee time to fix things (one time I had to explain to a guy that yes, the release is TODAY, remember? and these five things are broken while he was poised to literally dash out of the office at 4:00).
• Many good ideas you have to improve the user experience will conflict with the assumptions or preferences of stakeholders. It takes tact and tenacity to get stakeholders to re-examine their assumptions or buy in to solutions that may delay the timeline or require more resources. (No, the user who bought our product service plan won’t have the expertise or inclination to diagnose their own problem for us.) Sometimes you’re forced to make painful compromises until you can bring them solid data to support your proposed design.

Getting the job:

• Good, “intuitive” UX is largely invisible to a lot of people. The interface we spend a lot of time and effort designing will feel like “common sense” to a lot of people when we’re done. When those people are in charge of hiring, they either don’t know a UX designer is necessary, or underestimate the skill set involved.
• Employers often don’t understand that UX encompasses a range of disciplines and one person can’t/shouldn’t do it all. There are UX architects ferreting out requirements, devising flows, and wireframing things out. There are visual designers translating those wireframes into attractive, brand-compatible, functional interfaces. There are UX writers creating on-screen copy that’s clear, consistent, and appropriate. There are developers transforming the designs into actual working websites and applications. There are UX researchers conducting usability testing to identify user pain points and solutions. These are all distinct skill sets; any given practitioner may have some secondary “unicorn skills” but nobody’s an expert in all of these things.
  
  Here’s an analogy. If you want good music for your wedding, you hire a band or a quartet. You don’t hire this guy.

(image source)