Why block Firefox?

I came across an article in which some sites are blocking Firefox with a reference to the site:

The people who wrote that web page are stupid, in my opinion. First off, using the IE tab in Firefox is no an option if you are using Linux.

Second off, there is no loss difference between blocking the ads and completely blocking access, except that the person can't or won't buy from the site.

Third, if you use the plug-in "noscript", the javascript version does not work and then you won't be blocked.

Fourth, you can use "user agent switcher" to tell the remote system that you are using "IE", which is especially useful for the stupid sites which prevent you from using anything other than a single company's product which does not run on all platforms.

I would love to get a list of the sites which are blocking Firefox so that I can block them and not do business with them.

I am also thinking of blocking non-users of Firefox, just to make a point.

Update, just saw this article:

Study: Dumb People Use Internet Explorer