>Soldered-in RAM is not acceptable
Soldered-in RAM is not acceptable in SOME use cases, including perhaps 100% of the use cases that apply to you.
As for me, I'm fine with soldered-in RAM for devices that make no sense to have a RAM either upgraded or swapped out due to failure. I'm thinking "throwaway" things like "disposable" e-cigarettes; "appliance" things like routers, cable TV boxes, microwave ovens; embedded systems that won't be touched until it's time to replace them like the chips that are in my car radio or in a satellite; and much more.
I'm kind of torn about soldered-in RAM on my phone. Sure, I'd like to be able to upgrade it, but going from soldered or SOC-based RAM to user-upgrade-able RAM involves tradeoffs and costs that I may or may not want to make. Even if I want to make them, if enough people don't it's not going to happen because it won't be cost-effective to make a RAM-upgrade-able phone for the relatively few people who want it. Same argument goes for soldered SSDs vs user-upgradeable ones. Same argument goes for "super-thin" or "super-lightweight" tablets and laptops.
For "ordinary" laptops and desktops, where there is plenty of room for air flow and plenty of room for the extra space needed for user-replaceable RAM (and SSD) I agree with you: Soldered RAM (and SSD) is unacceptable unless the end user is demanding it.