how much is this necessary in order to make the Macbook's as thin as possible? In my opinion it looks like some of these steps make sense in order to really slim down the machine, but perhaps not all are necessary.
Well, I think it really comes down to this with every part they make or use:
1. Does it save space? (product appeal)
2. Does it save money? (efficiency)
3. Does it prevent unforeseen actions? (security)
#1 is important, obviously; smaller parts means an eventually smaller computer, but it also means that less can go wrong. It means less carting around millions of tons of junk between factories. Trimming down packaging alone probably saved Apple quite a bit in various ways.
#2 is both pragmatic (pay less to make a system) but also about the perils of mass manufacturing. Apple is too big now to sip-source; when they commit to a part, it usually means taking over entire factories. It's not a huge stretch to say that, say, a design that uses one less screw could save days of time before a product is ready to launch, simply because of the sheer overall numbers of parts required for their worldwide sales.
#3 is both paranoia and thinking ahead. Sure, as ifixit says, going with custom screws is maddening. But I doubt they are trying to screw over repair shops. It likely comes down to they had somebody sit down, do the math, and figure out that using non-standard screws prevents X.Y% of repairs which in turn saves Z dollars. When you're a company of that scale, even 1% is probably a fairly serious number to consider.
I haven't kept abreast of PC laptops at all and I'm wondering if they are also following Apple in this area? For example the Samsung 9 is a pretty slim laptop. Can you open it up and swap parts easily? I've googled for some reviews to try and find the answer, but I'm not a PC guy so I don't know where to look and I haven't found any good sources.
I think it's partially upgradeable? Depends which one you mean though, there seems to be a lot of generations for that one floating out there.
