Is Facebook lowering user expectations?

How many times have you been using Facebook and received the “Sorry, an error has occurred. We’re working on getting this fixed as soon as we can.” message?

This appears to happen fairly often (relativly speaking) from what I can see. I wonder if this lowers peoples expectations of what uptime they should expect from the big web 2.0 platforms? For instance, I dont ever remember getting such a message on YouTube… but then again a whole lot more people use facebook than use YouTube…

I guess my question is this… Is it acceptable to be having public downtime on such sites/services that are becoming such a part of everyday society? I would say no, its not. Were told that facebook has somewhere in the region of 10,000 servers! So goodness knows why with 10K servers they cant get a decent amount of uptime for most users.