"I believe people who don't know about dangerous spam are the same people who wouldn't know how to tick a checkbox in the mIRC options."
These would not be the same people who set mIRC to autoget anything they are sent? By default this is disabled AND file types are checked AND warnings appear. Na, they wouldn't know how to do that.
Would they be the people who don't know how to set mIRC to auto-open urls? Na.
Oh and of course the people who want you to see "mIRC!" instead of "http://backdoors.for.yu" wouldn't tell newbies how to enable this "cool new feature" would they? Na, of course not. The next version of §|ôÐôwñ script wouldn't have it enabled would it? Na....
I think that the people who most would prefer to mask the url are likely to be those same "people who don't know about dangerous spam", and the people who send it of course.