Pike/elmo — comment on commit 841720d4208799e6a0b55944ebff53740249cb50
File: apps/pushes/views/api.py line 55
By Pike:

It's not really a matter of "why", the json mime type isn't whitelisted, and if a cross-origin request would ask for json, the browser will pre-flight it. The whitelist for simple stuff excludes a whole lot of things, and I file bugs on any lib out there that violates that. jquery included, and harthur's bz wrapper, too.