Comment by wittrock

The real problem is the entrenched legacy software that uses BSD sockets. I don't want to even imagine the cost of rewriting all of that to use a different networking paradigm. POSIX certainly isn't the best way to do things, especially with the move to the cloud, but much of today's high-performance software today does fine with sockets. There are absolutely some hacks that are used to get around some inadequacies, but BSD sockets work, by and large.