Because half-assing the implementation is the way to go
Let’s deliver a broken version of accessibility in 10 minutes, that’s much better.
No, simply adding “colour filters” isn’t a fix either, and if that was the fix then a game wouldn’t even need to do that, there are plenty of apps that can already do that, a game doesn’t need to do anything for that (similar to how your screen warmth can change when it becomes night), reshade as an example of something that can do just that.
But thinking about the problem is ofcourse too hard, it’s easier to whine about it and act like you know how simple it is. But when we implement accessibly we do think about it, because people with accessibility issues deserve to get something that actually helps rather than the “10 minute solution”