Making /dev/random blocking optional doesn't help; in fact, it probably hurts, because it allows more Linux code to "safely" use /dev/random, and that code is dangerous on platforms where /dev/random does the old Linux thing.
I'm not saying /dev/random's blocking would be optional; I'm saying the driver backing /dev/random would be entirely optional. Making it a link to urandom rather than having it entirely missing just avoids breaking old (misguided) userspace that still uses it; breaking userspace would make the proposal less likely to be accepted. Convincing various userspace components to switch to urandom, and for that matter fixing the documentation to stop recommending /dev/random, is a separate battle.
