This is absolutely the case - in software, accessibility features are in many cases identical to power user and engineering quality features. Color-theme support is necessary functionality for color vision deficiency modes, labels and tags on UI elements enable screen-readers just as much as they enable automated testing suites, configurable keybindings make it easier to get your app working with assistive input devices. It's such a strong relationship that even bigcorps know it's a thing; I got talks about it during Google employee trainings.
If anyone needs further convincing, remember that the journey from power user to experiencing disability is inevitable (age-related sensory & skeletal-muscular decline) and in some cases, abrupt (traffic accident, keyboard/mouse related RSI). We all eventually benefit from accessibility features.
Yeah. If you ever thought it was annoying to have to spend two hours on the phone to get Comcast to cancel your internet, imagine how much it would suck to try to do that with a sign language interpreter sitting next to you, or with text-to-speech and speech-to-text systems in the loop.
