You did good, fuck IE and users who use them. Education by force.
It could be good to show alternatives, and leave it at there.
For the "enterprise" that can't change, well they can complain.
Fine. But why sound like such a dick? How about "We're really sorry but this website only works with...." ? or whatever. With that kind of attitude, I can absolutely promise you I am NOT going to copy-paste this url into chrome or FF.
Am just trying to help. If you think that language is fine, go with it.