Note that until FireFox came along, 99% of Windows users never even considered departing IE.
I disagree. This is just history revisioning. Even casual techies know that many were still craving for Netscape but it just kept bloating up and being buggy.
Internet Explorer did a Google Chrome, add a monopolistic comes pre-installed with a popular OS and with the right marketing it captured the majority of most people's interest.
If you like to play predictions, you could even say the latest version of Netscape is at the current point where most user friendly Linux distros are today. Featureful but bloated and still often times containing the occassional deadly bug for casual users who don't know how to troubleshoot.
Opera then was Adware and like the early Apple OS's, superior but never considered as a viable alternative. Macs today are highly popular in their niches. The same phase could be said for where Opera is going. Desktop market share wise, they're lingering at the bottom but like Macs, they're focusing to the future. Where Apple eventually focused more on laptops and portables, Opera is gaining new grounds with their browsers being on Wiis, cellphones, handhelds, PDA, etc. Of course it can be said that the company is still missing a Steve Jobs but how notable was the name Steve Jobs then to the mainstream tech crowd?
So to give Firefox credit for all their success like they came out of nowhere is a blatant disregard for all the circumstances that led them here. Remember before Firefox, the main reason why Firebird gained notoriety was it was finally Netscape that got what IE had going for while retaining most of it's features through add-ons while doing the right marketing.
This is pretty much the same pattern the Linux Distro worlds are going through right now. As Windows 7 and Leopard constantly add buggy or irrelevant eye candy, Linux developers are forging the "light on resources" ahead by stabilizing Wubi, improving MintInstall, finally auto-adding a separate user partition, taking advantage of the maturity of cloud technology to sidestep vendor lock ins.
All these while patiently riding under the upcoming bloatware and as the community grows, it could potentially do what Firefox eventually evolved from: A less lightweight Firebird that changed it's mascot and took advantage of the growing dissent and lack of true useful innovation from the competitors.
I guarantee you that had Firefox started like Firefox 2.0 or Firefox 3.0, it won't gather half the marketshare and half the add-on developers like it has now to leverage it's uninnovative architecture and 99% of those using Windows won't be considering switching from IE especially because if the Firebird product had just been delayed a little bit further, the popularity of IE shells would rise and everyone would instead be saying "Why do I need to switch from Firefox if Maxthon can do this anyway?" except for the few open source zealots.