wow... this discussion lost its sense. Why browser choice is so important? "Because your choice affect my choice."
Why browser is so important. Because browser is used to access internet. Some sites only works in IE, and why? Because of this thinking: "If my site works for the most popular browser, why should I care about standards, etc!?" Conclusion, if everybody JUST use a default browser, internet will not free. Internet will be IE only for example.
And that's why notepad, calculator, paint, defrag don't matter!