In all seriousness, what is going on with this? I've just been talking to my mate about this and he was telling me that he's heard Spanish reporters talking about this on the radio and they are very confused by this, along with Barcelona and Fabregas apparently. Barca have reiterated that Fabregas is not, and never has been, for sale. In addition to this, Fabregas' advisors are maintaining that he doesn't want to leave and are surprised by the bid.
I've just been thinking about this and the only reasonable conclusion I can come to is that we just tried our luck. Perhaps we hoped that a a good offer would tempt Barca, even if they wouldn't have entertained the idea in theory. In making a bid, perhaps we were hoping that Barca being tempted could create frictions and make the deal a possibility. The benefit of going public with our bid is that we can be seen to be attempting to solve the obvious issue with our midfield. If we don't sign a midfielder and Moyes is seen to have made no attempt then maybe there would be a backlash from the support. Hence going public.
On the flip side, the offer may be a success and we may land Fabregas. Win-win. That's the only reasonable explanation I can think of to understand our actions here.