I know it doesn't really seem important, but a good visual identity can help make it clearer who is supporting particular projects – and for a positive community organisation like Mozilla that's probably a good thing.
This has nothing to do with "brand identity".
edit: Though I agree with the vague collective sentiment that they're slipping. Still, I would never feed Google.
Yes, in the exact inverse way I'd want a non-profit like Mozilla to work.
By the way, do you understand how marketing works? Mozilla is not a lifestyle or luxury brand, and nobody cares about those things in browsers.
Firefox got a huge market share back in early 2000-2010 because it had a good product -- not because of branding. Heck, it wasn't even an official Mozilla branded effort at the start, just a project by some community members.
http://www.brandingstrategyinsider.com/2015/01/18-different-...
Is it possible you got used to the incorrect rendering or something? How do Edge and Safari look in comparison to you?
First of all, we're talking on the Mac, and with Retina display.
Second, "used to the incorrect rendering"? What's to be used? Firefox consistently has had not only less smooth font rendering, but also botched layouts and worse zoom behavior.
(Safari is pretty much close to Chrome. Edge, I don't use).