You are deliberately confusing presentation for semantics, which is discriminatory. The WCAG directly mentions not doing this. You cannot achieve AA conformance when you attempt to force this on your users.
For example red means stop and green means go to many people. When color is the primary means of status description that is discriminatory, because blind people cannot perceive color in any way. The status must be described in some other way equally for all users, but it can be colored red/green by CSS for increased usability. The same goes for page structures like menu bars. The standards even provide examples with ARIA.
CSS is only a factor for people with motor control limitations when interactive controls are too close together to be accessed uniquely with a mouse click. If this is a concern for you have somebody with advanced Parkinson’s usability test your site, otherwise turn CSS off for all other accessibility testing.
> When color is the primary means of status description that is discriminatory, because blind people cannot perceive color in any way. The status must be described in some other way equally for all users
Yes, agreed. That's why you should provide a non-colour-based indicator of the status, AND ALSO make sure the colours work for partially vision impaired people (or colourblind, etc).
If the information is technically accessible, but in an awkward and hard-to-use format compared to the sighted version of that information, then it's not really accessible. Making colourblind people read awkward labels when you could just as easily use colourblind-compatible colours is inaccessible. I am not confusing presentation and semantics, I am just saying that both are involved in creating accessible content.
For example red means stop and green means go to many people. When color is the primary means of status description that is discriminatory, because blind people cannot perceive color in any way. The status must be described in some other way equally for all users, but it can be colored red/green by CSS for increased usability. The same goes for page structures like menu bars. The standards even provide examples with ARIA.
CSS is only a factor for people with motor control limitations when interactive controls are too close together to be accessed uniquely with a mouse click. If this is a concern for you have somebody with advanced Parkinson’s usability test your site, otherwise turn CSS off for all other accessibility testing.