It doesn't take a rocket scientist to support http/1.1 pipelining on servers. It's harder to implement in proxies. Much of the creepy middleware on the Internet

It doesn't take a rocket scientist to support http/1.1 pipelining on servers. It's harder to implement in proxies. Much of the creepy middleware on the Internet would break down in nearly impossible to troubleshoot ways when browsers pipelined requests. So they forked the protocol as a bypass.