In my opinion there is a commonly misplaced emphasis on sites being accessible by blind or visually impaired people, this is only part of a much bigger picture.
They need to be usable for everyone which means you need to consider your audience. People like to have the accessible badge and the government has made things worse by introducing the requirement to be level 1 WAI compliant - which really is nonsense.
For example consider your target audience being people with mental difficulties they need a site that engages them by perhaps making things drag and droppable, perhaps has flashing/moving content, has big fonts, is very, very simple content with lots of imagery and little text.
Clearly this flies right in the face of a site for people suffering from severe epilepsy, or visual impairment, or cerebral palsy.
Even the WAI guidelines themselves are contradictory. For example, one element of level 2 is that you should not have the same content or words on the page linking to different places or different content on the page linking to the same place.
However our research from working groups is that people needs as many ways as possible to get to the same thing on one page since different people navigate in different ways.
In this scenario so much of accessibility is not even about people who have a disability – it’s about making your content easy for Joe Bloggs to find.
The bottom line for every organisation really should be: who is my audience, is my site easy for them to use and does it do its job well?
The WAI guidelines are a good starting point but should not be a rule book......and in fact there is even the concept of "self certification" which basically means I've done all the WAI checks - I fail but don't care because WAI doesn't really understand what my site is for and I think it’s fine for what it’s used for.