I bet that despite all the talk about the importance of being upgradeable, the actual proportion of PCs (including Macs) that ever get upgraded in their life is tiny - a small fraction of 1%. And I bet Apple has data on this that tells them that. So then why would they bother making their devices upgradeable? Especially given the risks and support headaches that creates (and Apple will also have data on what proportion of Apple Care support calls are generated by issues with user-modified RAM). The "server grade users" that you talk about just want a fast device that is highly reliable - and actually accessible components conflicts with reliability.
In reality, when people here talk about upgradeability or "user access", they are almost always talking about one single thing - being able to add their own RAM to new iMacs to undercut Apple's own RAM upgrade pricing. So that becomes entirely a commercial decision for Apple. Does the increased revenue from being able to charge for RAM upgrades (revenue that is currently going to third parties instead) offset the potential reduced revenue from users who no longer buy iMacs. And I bet Apple has done that analysis and come to a decision.
That is a good way at breaking it down, and makes sense that apple isn't in a hurry to add more upgrade options.
My biggest complaint is that everything is priced to make you feel like you are getting something better, but not as good as it could be for "just $200 more" or something like that.
They make the base models so unappealing that it's almost a given you will purchase at least one upgrade, but they make the following upgrade just a bit too much but just cheap enough to possibly entice you to want to get it....and if you don't, you still feel like you didn't get enough out of the purchase.
So it's almost like I have to spend $3,500 to get the 27" + 512 SSD + 16 gb ram + i7-7700k just to feel like I'm getting my money's worth out of the purchase.
To get that with a i5 base model is still like $2,900 and I can't fathom paying almost $3,000 for a kaby lake 3.4ghz i5 that is pretty out dated by this point. At least the i7-7700k has great single core speed and is somewhat future proofed and can keep up with the hexacore chips.
So it's like your are damned it you do, damned if you don't.
* 21.5" i7-7700(non-k) + 512 SSD + 16 gb ram + CD Drive + Logic Pro X + Track Pad + Tax = $2,850.
Those are the specs I want....I just want them in the 27" and they don't offer that processor.
I'm seriously considering the 21.5" and then just buying a QuadHD Monitor or 4k Monitor...27 or 32" and paying $350-400 for that, and having dual monitors.
* Also eliminates retina screen burn in problems as well if I use a different screen......I may not even use the 4k 21.5" screen.
I don't need anything more than 1080p HD honestly...I'm just using it for Logic Pro X.
Every day I come up with a new option that sounds good and then another the next day that sounds better and so on....vicious cycle...I wish Apple would announce the 2018 imacs already and just get it over with.