What kind of misinformation are you trying to spread here? GTK+ has accessibility built into the toolkit itself - it's not optional, and it's always on. In fact, GTK+ had it before Qt did - ATK was written back in 2001 to be a part of GTK+, and the screen reader Orca is written to use GTK+ and the platform agnostic AT-SPI layer. It would take a full ten years for Qt to add an implementation here.
The parent post is saying it doesn't plug into the native a11y, which is true. Running the at-spi daemon on windows/mac would work for some things but it is obviously not ideal.