I agree with what you're saying. I think there are reasons to worry about the future of this club but to throw the toys out of the pram after one game and after the sale of one player is ridiculous.
However, I wish I could share your optimism about Juventus at the minute and that all will be fine by 2012. After relegation to Serie B the 3 seasons that followed were very encouraging IMO. We came straight back up in first season and were a strong side again in Serie A for 2 seasons. I'd even say we recovered from the relegation as best as we could have hoped for. However, the collapse of this side in the past year is worrying, we've went backwards. Patience is exactly what is needed but none is being shown. The club are rushing into signings and various managerial appointments without any clear thought or structure it seems. It appeared Guus Hiddink was one of our top choices but we weren't prepared to pay the wages he was asking for, we then went for Rafa (which would have been an awful appointment) and that never came off either. Who knows where Del Neri was on 'the list' of our most wanted managers. It's the same with various transfer targets, we seem to designate who we want and when we don't get them we panic and rush into a solution. A lot of money has been wasted in the past few seasons. The fact we have made a number of loan signings this summer isn't a clear sign of direction, it's another example of short term fixes and papering over cracks.
Last season was a wake up call and the club really needs to get it right this time, it's a delicate stage in this club's history at the moment and we need strong management and guidance, can't afford to many wasted seasons. Maybe the pressure from the fans isn't helping but I think a more calculated approach is needed for the club.