I agree that it's a stupid idea, but there is almost nothing about text that makes it special. If the HTTP/2.0 standard is actually a standard, then it will be pretty easy to make an app or a plugin that translates it.
There's almost nothing about English that makes it special, but I wouldn't recommend documenting the spec in Klingon. (To be fair, you agree that binary is a bad idea.) Or hey, would could use APL for the reference implementation!
Intrinsically, you are correct: there's nothing much special about text. But the significance of text isn't intrinsic: it is extrinsic. Text is special because it's standard. We have a rich selection and history of tools, techniques, idioms and sober experience to draw on when it comes to dealing with text. With a new binary format we would have none of that. Your imagined translator has a lot of work to do before it can match up to the existing capabilities of text-oriented tools, let alone exceed them. Unnecessary binary formats effectively fork the development infrastructure.
If you ask me, it makes about as much sense as replacing the Roman alphabet with Chinese idiograms for English. Chinese characters are for more information dense: you can fit more on a page and you can read it faster. In many respects it's more efficient (it has even proven effective as a shared written form for diverse spoken dialects). That doesn't make it a good idea, regardless of the availability of translators.
We have plenty of historical examples of text protocols providing advantages over their binary equivalents. Do we have any good examples of the opposite: in which a binary protocol replaced a text protocol and proved superior by virtue of being binary?