Yes fans are nuts and have unrealistic demands, but there are unrealistic demands like the browns and then there's unrealistic demands like the patriots. Maybe the Jets vs. the Steelers would be a better example. The Steelers seem to set more realistic expectations and if they can't be met in the time given time, and they do give time, they move on. It even seems that their fans give time for improvement to be made.
The Jets and Browns seem to have no expectations just unrealistic shooting for the moon type of plans where pretty much anyone can be blamed for the failure of the team on any given day and fans will call for a new, that person. They're not trying to build a team they're trying to fix it. I much prefer the build and move on and keep building model. What part of either of those teams (Browns or Jets) is really coming together and appears to be built?
I admit, it's hard to tell what's really going on from a fans point of view, so I'm guessing just as much as the next guy.