When I'm debugging HTTP, 98% of the time it's either with curl, Wireshark, or by dumping state in my own server-side code. Things like curl will work just the same. Wireshark has an HTTP/2 plugin; given their history, I'm sure it'll be excellent by the time there's much HTTP2 in the wild. And anybody writing server-side code is hacking together their own tools anyhow.

The rare occasion where this will be a big difference for me is telnetting to port 80 and typing HTTP by hand. Honestly, I only do that out of habit; I can do the same things just as well with curl. But even when HTTP/2 ships, I'm sure it will be at least a decade before servers stop supporting HTTP/1.1. Probably longer. So I'm not expecting this to make a big difference to my debugging habits.

The tools don't exist right now, but they will become available. Existence of tooling follows demand. HTTP 2 has a large momentum so tooling will exist.

I'm not willing trade away the human readability of HTTP/1 for a a performance gain that I really don't need.

What about tools for reading corrupt binary HTTP/2 frames?