The proposition for me is whether to take a class or two on this in the course of pursuing a graduate degree in CS. I'm not considering a career in HCI research.
> It's literally one of the trendiest things in design
Ask a person with low vision about how the rollout of "accessible buses" in Chicago affected their transit experience. I'll give you a hint: it made things worse and more difficult. My sister, who is blind, complains about it all the time. When a friend of hers, who is also blind, called in to say that she couldn't read the stops on the displays in the new "accessible buses", the response (after months of silence) was "we asked Chicago Lighthouse how to design the display, and they said standards called for a bold font and contrasting colors, so we're compliant". In fact the display has a much smaller font than the old LED displays. The colors are bright yellow and bright blue, which are "contrasting colors" but have very little luminance contrast, and they're overall harder to distinguish despite the bold font. Why were these colors actually chosen? It has nothing to do with contrast or accessibility— it's because they're the brand colors of the Chicago Transit Authority. And when actual blind people call them to tell them this doesn't in fact work for them, their answer is that they don't give a shit and that they're not interested in changing anything. (Changes would be physically trivial; the new displays are big-ass LCD TVs.)
This is the norm for accessibility initiatives in the real world, because disabled people are rarely directly involved in the design of anything.
If you've lived your whole life in a world in which accessibility concerns are purely theoretical and/or external to you, I suppose it's easy to have faith in "trends". But nobody who has actually navigated the world with disabilities does. Frankly, the only circumstances in which I'd be confident that an HCI class would not be primarily grounded in the primacy of the visual and the assumption of normal vision is (a) if I've reviewed the curriculum of a specific course and the curriculum indicates otherwise or (b) the course is taught by a blind person. Even so, I'm on the fence— maybe I still want to take such a course.
I'm in the early stages of planning to go back to school here, thinking out loud about whether HCI is a corner of computer science worth visiting for me and sharing that question as part of a perspective on "design" and how I relate to it. I don't need help remembering that accessibility research exists, thank you so very much.