An overrated slow loading web browser which gives users a false sense of security. Will not stop malicious downloads or viruses. Stupid users will still manage somehow to infect their machine with the latest virus/malware.
Also comes with a gimmicky extension facility to load more crap into the browser and deviate away from its core use of web browsing.
Plus, with every new release you have to reinstall all these damn extensions again. So much for usability, eh?
Why have all my extensions stopped working with the new release of Firefox?