They are trying to create a market where you as a consumer think of the ‘laptop’ as one unit
I think as a market strategy, it’s GREAT! If I ran Apple, I would do the same thing. The reality is, the market for non-savvy tech consumers who just want a laptop that “works” is MUCH bigger than the market for hobbyists, tinkerers and hackers.
Now… occasionally you have one of the latter three who buys a Mac and wishes they could upgrade the hardware components individually. I agree that sucks and I would be pissed off to. However, the risk of alienating those people was acceptable to Apple because of the margins they could make on everyone else.
On a side note, Apple has done a wonderful job of even fusing together the hardware and software. Since you only see OSX running on Apple devices, it has created an unprecedented level of unity between hardware and software. The experience is SO cohesive that I think that’s what most people pay for. The entire ecosystem feels clean and safe. That I cannot take away from Apple.