Also known as: why you shouldn't trust a company who makes their product intensionally inaccessible with allowing you an accessibility workaround Update: I've been informed that hCaptcha now has a text captcha option. The bulk of this blog post still stands. Thanks to D Hamlin for the ...
Some people are legally blind as well. CAPCHAs are often either small sometimes blurry pictures or a deliberately blurry font. Someone with dyslexia may also struggle to read some CAPCHAs.
So banning someone over this is just reprehensible and ignorant unless there is truly evidence that they were trying to build a bot or otherwise maliciously use the site. :(