I've been thinking, and I think I solved the puzzle:
This move by Ubisoft wasn't really an obviously misguided attempt at stopping piracy, no. It was well thought out and deliberate, we just can't see the forrest for the trees. Lemme explain:
Ubisoft is deliberately trying to destroy PC gaming, by annoying the fuck out of everyone wanting to play their games on PC. They are totally aware of the fact, that no matter what DRM or copy protection they use, it will get cracked eventually, usually in a few days before the game's release. So, they thought, wtf, let's kill PC gaming altogether, and herd them to buy consoles. "If we annoy them enough, they will stop playing on PC and go buy a hassle-free console". Sure, it's totally obvious now. Making games for consoles are far easier than PCs: unified architecture (no need to take different configs, OS-s, whatever into consideration), simpler dev tools, shorter development time and it's way more cheaper, etc. And, for what it's worth, piracy is still lower on consoles. The sales they lose on the PC, they will get it back on the increasing console sales when disillusioned ex-PC gamers fold and go buy a console. Win-Win.
This is not an idiotic frontal assault against piracy, it's a well thought-out, insanely clever evil plot against PC gaming. Yea, some may think it's just another conspiracy theory, but still, it's a better explanation than "Ubisoft went insane and stabbed itself in the back". Think about it...