The [dev tools colorblindness] simulation is inaccurate, using color matrices with no scientific basis. While the source cited in devtools/server/actors/accessibility/constants.js does not list its source, the matrices appear to be the "colorjack.com matrices" [1] (and do not originate from the scientific literature). As far as I'm concerned, this is worse than not having such a simulation at all, since it gives people a false sense of accommodating individuals with color vision deficiencies.
This kind of disparaging really doesn't contribute anything in open source. It's not perfect, it's a work in progress. We don't disparage something, we bring a pull request with a wrapping text that explains why it's an improvement. And see, that gives the author the credit for contributing whatever they think is a solid solution, too.
