Te be fair, they are actually trying to reimplement a subset of SCTP. HTTP over SCTP gets all of the advantages of SPDY (which HTTP2 is based off of) except for the header-compression (which could have been separately implemented). Unfortunately NATs don't handle SCTP so you are left with implementing SCTP over UDP, and NATs also don't handle UDP as well as they do TCP, since UDP is stateless.
It's more than that; pretty much nothing in the wild handles SCTP, and they wanted to build something that can be gradually transitioned to (it will be a rough transition for sure, but it's still supposed to be HTTP).
HTTP's simplicity is the reason it's been so successful and proved so flexible. Please don't throw it away.