Not sure what "spends no time at HN" means. Martin is an unusually excellent software engineer by almost any measure, as evidenced by his years of impactful open-source development - 0MQ being just one example.
And Haskell wouldn't make sense for a project like this, only because of some of his goals with the project - which include: to eventually have it integrated in the Linux kernel; to make it easily usable by code in any language; to have it easily and universally cross-platform; etc.
(Dang... did I just feed a troll?)
"C" gets you there, if you keep clean "C" interface, and don't let exceptions escape if you have been somehow using C++ internally.
I've had no problem using zeromq directly through the luajit ffi bindings for example.