Well, as bridge-burners go, accusing 95% of your (now former) fans who buy your games for the PC of being pirates is a good one.
Look - I am a PC and a Console Gamer. I'm relatively wealthy in that way. I prefer to play games on my PC when available but I have nothing with games being on Consoles. I understand, I perfectly understand why some developers are taking a step back from making PC games - they are generally more difficult to make, and investors usually want the developer to put some sort of bad DRM on it, and that makes the community upset and at the end of the day the console market is just.... well, larger. If a developer doesn't want to make a PC version of their game, that's FINE. It's a business decision. Not necessarily the right decision in my opinion, but that's their call to make. If they don't think their game will sell on the PC, then it's obvious why they wouldn't want to contribute resources.
But a simple "Sorry, we're not developing a PC version for business reasons" would have sufficed. To make somewhat ludicrous claims that "95% of PC gamers pirate" is silly. Steam makes a ton of money. Skyrim sold gang-busters on the PC. 95% of PC gamers do not pirate their games. Hell, I doubt more than 30% regularly pirate their games.
If Skyrim, Portal 2, Batman Arkham City, Fallout New Vegas, Mass Effect 2, Saints Row The Third can all do relatively well on the PC, well enough to turn a profit for the developers, then the PC market is hardly dead or infested with Pirates now, is it?
Maybe Ubisoft just aren't confident in their ability to develop for the PC.