this line of thought just stems from the conflation of graphic design and interface design. the skill in demand is the latter. to be good at it one needs to be able to be proficient in html, css, javascript, and have basic abilities in whatever server-side technologies are in use.
so, yes, these folks will be hard to find. just like any other good engineer, they'll either have a job, be kicking ass, or doing their own thing. c'est la vie. try offering a wage they can't refuse.