I hate it too, but to be fair we signed up for this when we decided to install Firefox Nightly instead of the stable version. As the author of the change writes:

> This is a partial implementation of the URL bar, this will have to be addressed in phase 2 when the address bar is reworked.

Now, if this partial implementation makes it into the stable version as-is, that would certainly be a failure of release management, but otherwise it's just the nightly acting as testing ground for half-baked stuff.