I must say though not having a colourblind mode seems kinda shitty, having some text in different colours doesn't exactly destroy the game. Plus there are braille e-book readers so pretty much every book is available in braille or has the ability to be.
colorblind mode isn't necessarily an easy task since players may not agree on what objects need to stand out, and in what way, that balances potential intrusiveness with usability
some games go about this by differentiating reds and greens to cover the most common types of colorblindness, others make some colored elements shaded in different ways (stripes, dots etc.), some might go so far as to alter the contrast of world vs. interactive objects
I'm not anti-accessibility, but I am against tacit or explicit requirements that all creators must adhere to
there is a difference between accessibility that can be added to media by third parties, such as braille modes for all books or blind-friendly movie dubbing, and accessibility that is insisted upon being incorporated into the base product, pushing those costs onto every consumer, for all of three people who may ever use it
I am ok with a game maker deciding that it isn't worth it, as long as they're ok with slightly fewer sales
same situation as a game maker deciding to make a game full of scantily clad women, and being ok with missing out on sales from era types