I HATE Firefox. I installed it three times on three seperate occasions and I uninstalled it each time. I can't get adjusted to the way it is set up and it stopped working one time. The first two times I installed it, it wouldn't transfer my bookmarks like it claims to do, the plugins were lame and the difference in loading a page on IE and Firefox wasn't that big of a difference on my connection.
So it can autoblock spyware and pop up ads. Ever thought that some pop ups are needed, for downloads and private message notices (Back in the old forums)? And what kind of sites are you going to that gives you a massive surge of pop up ads and/or spyware that you need to install a brand new browser? I'll stick with IE and a good program that can get rid of spyware like Ad-Aware SE.
I'm also tired of hearing solutions to computer related problems involving me to get something. If I have a problem with my PC, I'm told to get a Mac or install Linux on my computer. If I got a problem relating to the internet, I'm always told to get Firefox and sometimes treated like I am an idiot for using IE. If I can't burn a CD using iTunes or another media player, I'm told to get with the times and get an iPod.
Telling people to get certain programs/hardware/accessories may be great now, but think about this: If everyone starts to use a Mac or Firefox, then all of the jackasses who spend time making spyware, viruses and other annoyances will start targetting Firefox and Macs.