Actually, a site that is structured well enough to be usable in text mode browsers is already more accessible to all users than most of the “beautifully” designed examples.
There's a different kind of incapacity involved: incapacity to control your device and software to have them suit your needs. The reply assumes that user has no other option except to drool and stare at what website author chose.
this generally isn't how designing with cognitive or neurological disabilities in mind works, we don't want the user to have to make adjustments in order to use a website as this only creates more friction. Not to mention the fact that we don't assume that the user is knowledgeable on how to make those adjustments, especially with the senior population which is a large segment of the cognitively impacted population who are using the internet.
unlike with the blind or low vision population, those with cognitive and neuro issues often aren't aware of assistive tech, often aren't familiar with the accessibility settings on their devices, and sometimes aren't even aware of the disability they are dealing with and are undiagnosed.
The users will never be knowledgeable if no one is teaching them anything. They also won't make adjustments if the ability to adjust itself is removed because It's Better This Way™.
I am aware that the site is original for the sake of originality (slanted divs look awful on my system, too). However, the advice to stop and find out what is wrong instead of just keep doing what everyone is doing is pretty sane.
There's a different kind of incapacity involved: incapacity to control your device and software to have them suit your needs. The reply assumes that user has no other option except to drool and stare at what website author chose.