Too Bad
I have been in the software engineering business for over twenty years and I have run into a large number of IT "geeks" I would not want on the helpdesk. I have also run into a large number that handle customer service well also. You seem to be in the first group.
The customer doesn't care how you feel about it. They will just walk away and use your competitors. There are more than a few people using IE. In fact, there are enough out there to seriously hurt your bottomline. Your opinion doesn't factor into it. Whether you can sustain business by alienating customers matters infinitely more.