In what sense is TCP/IP master-planned? TCP has tons of options, and one of its key components, the congestion control algorithm, is unspecified and left up to client choice. Both of these facts have led to significant improvements, but even greater improvements were obtained by dumping TCP altogether, in large part because TCP ossified due to middleware behaving as if TCP were master-planned when it isn't. TCP, at least, is an anti-example to your point!