There's also a pretty big opportunity/time/effort cost to contacting Apple support, describing your problem, fighting with them over whether the defect is covered under warranty, actually packaging the thing and shipping it to them, waiting for the fix/replacement, hoping the replacement isn't similarly screwed up, and setting up all your programs and files again when they 'fix' the problem by wiping your machine or giving you a new one.
That's correct, but as a parent said, this kind of issue is very rare. I can't actually remember another mac os upgrade actually bricking machines. I may be wrong, though.
What's way more common is random hardware failures, unrelated to the OS. I've never had to deal with apple support and hope I'll never have to, but HP enterprise support isn't frictionless either. A colleague of mine had a swollen battery, which wasn't user replaceable (guess not only Apple has bright ideas). He called up the support, which went relatively fine but in the end he had to send the computer in for repairs for two weeks and was advised to save his data as the machine would be wiped. Luckily removing the SSD was possible and didn't void the warranty...
I'm sad to say my experiences with Apple support for my work laptops have been palpably worse than my dealings with my state's DMV (to use the stereotype of 'bad customer service'). I am currently stuck waiting for a screen replacement for a 6 month old 16" MBP (something that was promised in 3 days but I found today, after 4 calls and as many answers, that it might be ready this week); I'm using a 4+ year old MBP in the meantime - the latter needs a battery replacement but my numerous encounters with Apple support/Store have made me generally allergic to dealing with them. If there's a magical Apple cs experience that exists, it certainly has eluded me every time. Edit0: syntax.
