Having worked in IT for a long time now, I know that this is essentially a small computer. I am accordingly understanding of when and where it should be acceptable to become unstable.
To claim that the expectations should be set for instability is really selling the system short. There is no reason to have an expectation of instability. Yes, there is a lot you can do to decrease the stability of the system because the OS is fairly open and flexible, but there are changes that you can make where you should expect a decrease in stability (using SetCPU, modifying system files), and there are a lot of other changes (the vast majority) where the system should handle problems gracefully. Rebooting is not handling it gracefully. Force closes are graceful.
In the last, oh, maybe 5 years I can probably count on my fingers the number of times my home computer has crashed during use that required a reboot to become functional. Systems don't have to be unstable. I don't agree that having an open and flexible OS - and leveraging that fact - by necessity is going to cause crashes. A well designed OS will be robust enough to tolerate a certain amount of misbehavior from applications.