Yes, and no. Different hardware platforms and operating systems have different levels of requirements, and success at meeting those requirements.
I've been a professional programmer for 27 years. I work on a so-called "mission-critical" operating system, some of who's customers (e.g., stock exchanges, steel mills) have a five-nines or even six-nines reliability requirement (i.e., 99.999% or 99.9999% availability). That translates to a few minutes per year of allowable down-time. We meet that requirement regularly. I'll grant that part of the success comes via various forms of redundancy (e.g., clustering, where you can do rolling upgrades of the various nodes in a cluster to install patches, upgrade to new versions of the operating system, etc. while production applications continue to run on other nodes). It is harder to meet such requirements with single-system configurations.
Sorry to derail the thread a bit, but my point is that not all systems have similar characteristics with regard to reliability. Back on topic: Apple have done a pretty good job, in my opinion, with regards to system reliability for a consumer-level system.
Of course some computers/servers will just have to work all the time without any problem. It would be a mess if the bank online banking server suddenly stops working... I can't imagine doing the job you're doing. lol I'd be pretty stressed out all the time if I were you.
