Hmm. Here's some other computers released under Jobs' various reigns:
Apple II: The lid just unclipped and there was a row of expansion slots inside.
Lisa: I believe it had internal expansion slots
NeXT: ...had expansion slots (and Unix).
Power Mac G3 (Blue & White): tool-free access to its internal expansion features.
Power Mac G5: Again, slots, drive bays, tool-free access beyond the call of duty...
Mac Pro (cheesegrater): Slots, drive bays, tool-free access.
xServe: internal ram & expansion slots, removable hard drive bays...
MacBook Pro: easily (very easy, by laptop standards) upgradeable RAM and hard drive (intentionally so - with instructions printed in the user guide) until 2012.
Looks to me like someone who clearly understood the difference between a computing "appliance" and a pro workstation. From the release of the iMac through to 2011 - when the Mac Pro first started to wither on the vine there was always a powerful, versatile, expandable, easy-to-open option alongside the "appliances".
Methinks people are over-extrapolating Jobs' well-publicised original 1980s vision of the Macintosh range as a sealed appliance to some sort of dogma that all computing devices need to be like (original) Macs (or, indeed, iPhone/iPads).
It seems strange that someone who thought the future was only sealed-unit appliances would have allowed the G3 tower or the Cheesegrater - which the designers went out of their way to make easy to get inside - to be released.
In other news, Jobs could easily have hidden Unix away from the users (just like Android hides Linux) yet OS X shipped with a terminal app + a complete development suite (including all the usual Unix tools and compilers) "in the box". Even with the famously closed iOS, it is relatively cheap and easy for anybody to register as a developer (c.f., say, games consoles, which are pretty much serious-callers-only).
Sorry, but the idea that Jobs was single-mindedly pursuing sealed, closed systems for everything isn't borne out in his actions. That one is down to the new management.