I think it would be entirely reasonable for the person maintaining a Ruby binding for sqlite to follow the sqlite documentation and close any bugs telling them to go against that documentation, yes.
It goes against the Linux kernel documentation, yes. As has been pointed out to them, it doesn't go against the documentation on OS X or any of the BSDs. But they engage in the same behavior on those systems.
Well, perfectly reasonable to take the intersection of capabilities rather than special-case each platform. AIUI the behaviour of /dev/urandom and /dev/random is the same on OSX and *BSD, so there's no problem with their behaviour there.
