People can disagree all they want about SSL interception in a corporate environment (for good reason), but it's here to stay. When a corporate user downloads Firefox, tries to simply go to Google and gets a cert error page, they're just going to go back to Chrome because the process of exporting your company's CA cert and then importing it into Firefox so you can use the browser is just simply not feasible for most users.
My experience has been that most desktop IT teams don't have the resources to fine-tune browser configs on endpoints around things like corporate web filtering proxies so they just jam the cert in the OS store and call it a day. You can use Chrome, IE, or Firefox if you know how to get and import the cert (which most users do not). Sometimes users would submit tickets saying they wanted to use Firefox but couldn't get to any web pages, to which the IT team would reply "We don't support Firefox, use Chrome or IE" and that was that.
That's pretty sad, considering the fact it's the only mobile browser not only with the support of extensions, but the same extensions as the desktop version.
Future might not be that grim for mobile Firefox actually, with more and more modern Android smartphones and tablets support more and more RAM, and 4GB is pretty much standard.