Afterall, how many IRC servers do you know that run atop of Windows boxes? I imagine the number to be very small.
Because Windows hosting would chew up their budgets for a start. How many IRC networks could afford the hundreds of thousands of dollars it would require to run 10 - 20 NT servers running commercial software? I would say none at all apart from those that get such hosting either subsidised by ISPs (a big ask) and/or paid for directly by subscription to an ISP (once again a big ask as you are asking a business that is responsible to shareholders to give hundreds or thousands of people a free ride at their expense).
That said, I don't give a damn about reputation. Reputation is more often than not based on urban myth rather than legend. On that note if my network can run NT boxes for 5 - 6 years with Microsoft Exchange, Chatspace and ConferenceRoom with no problems at all then, aside from affordability, I cannot see why that can't work elsewhere. It's not like a pocketfull of networks around the world are performing miracles.
The rest of what you said I don't disagree with because you just said what I did, albeit a different way.
