I am going to brush aside the fact that you installed the software and were advised of a 30-day trial and once you crossed the threshold of that 30 days you were still able to use the software going beyond the limits set by the author and by your own expectations seeing as how you knew the software could die at any time after 30 days.
But...and this is a serious question not trying to get a rise out of you or flame you...why are you upset that you got a longer trial period than was advertised or you expected?
However, that question is just to satisfy my own curiosity. Onward to other things, having read the thread you linked to the author states that on start-up mIRC randomly chooses from a number of different messages including the one you got demanding for payment. Have you tried re-starting the program a few times to see if the app randomly chooses one of the other, less restrictive messages? Have you tried a clean install of mIRC?
If neither of those work it sounds like you at least are given a link to buy the app at a discount, maybe even as high as 50%.
Oh, and about the rant...what are you ranting about exactly? First you talk about your situation with mIRC then you rail against freeware turning into shareware which, you quickly point out, mIRC doesn't fall into this category. So why did you bring up mIRC at all? And if your main beef is with mIRC, why bring up the freeware/shareware thing?
Maybe I missed your point, too, but I'm trying really hard to see it. Help me understand.