This is partially true. It all comes down to the perception, accurate
or not, that if you're blind you must use windows. How this got
started I don't know, but in my experience linux can do most things as
well as, and in some cases better than windows in terms of
accessibility. Orca does a very good job at what it does and I'm
continually frustrated that the blind community in particular is among
the most stubborn and ungreatful of linux converts, often switching
back after a few days because they "think" they need windows for
something, and trying to convince them otherwise is like talking to an
apple fan