But by and large, blind people don't buy auto insurance because they don't drive and they don't buy paintings because they can't see them. Forcing these businesses to invest excessive efforts to serve 0.0001% of their potential target audience is idiotic.
And no, I'm not going to say what we sell because it's not important and this was clearly an extortion case.
It seems to me that what you sell is the central issue here, as you're claiming that blind people wouldn't be interested in it. I'm not really willing to take your word for it, given the other examples you've used.
In the case of car insurance, it's obvious that people don't only buy insurance for cars that they drive. Consider e.g. an employee of a company looking to buy insurance for company cars.
There are also lots of blind artists and blind people interested in visual arts, as you can discover from a simple google search.
It's worth remembering also that many "blind" people are partially sighted, so that they may be unable to read text but still appreciate visual arts in a direct perceptual way. On top of that, there are people who have lost their sight, and who may still have a keen interest in the visual arts formed when they were still able to see.