Why is it so unlikely? The simple fact is that demand for the internet is inelastic. There is no good reason to not install Firefox. It is open-source, standards-compliant, more secure, as fast (if not faster) than IE. All it takes is for companies to say no - you have to spend 5 minutes installing a different browser (and you'll be glad you did).
You're going to have lots of fun losing 25% of your customers (more or less depending on regional IE usage), many of them companies with oodles of cash. Heck, here IE usage is 14% while Firefox is 31% and Chrome 47%, according to StatCounter. Not as bad as the US, but still a huge piece of the pie.
Sure, it makes technical sense - IE sucks (well IE 9 and 10 are much better, but still).
It makes NEGATIVE NINE THOUSAND business sense - you've got to be crazy to refuse to support IE 8+.
Let's say Google said it. "If you want to use Google, then you need to stop using IE." There would be some complaining, but they'd get it done.
That's where the "balls" part comes in: you have to tell your users, that you just don't support their platform. Happens all the time, but for some reason browsers are treated specially and we all live in fear of losing the IE market share.
Someone did a calculation and decided that the business cost of supporting IE was worth the additional customers. It's not about balls, it's about cost benefit analysis. Us developers just hate IE because it's so different than all the other browsers.
