That's because those laptops were specifically designed to not be easily repairable. The new ones are complying with EU regulations, and so are easier to repair.
They were designed to be as small as possible, which sacrificed internal access. I doubt they purposefully made repairablity difficult. It just wasn't a major factor when 90% of the time they just give you a new laptop when you show up at Apple with a broken one (with a warranty or Apple+).
What makes you think it was unnecessary? Sockets are good for expansion but they increase failure rates and the extra distance increases latency so losing it is one thing helping push unified SoC performance.
Meanwhile, I've never had a socket failure, and I've upgraded the RAM on the 2012 mac I am using 2x now over its life (once to get to 8gb, a second time when users reported the computer could take 16gb despite what apple says). If I had soldered ram then I would be saddled with 4gb ram total and this computer would not be easily running mojave and allowing me to post this comment with 3 dozen tabs open in the background.
Again, I’m not saying that sockets are entirely bad but remember that the claim here is that this was just a cash grab when there are valid engineering trade offs. You’ve been lucky at n=small but DIMM failures was a relatively well-known thing to troubleshoot - notably more common for laptops which see more shock & vibration - and while having that expansion capability is certainly nice, it also made the system slower over the course of its lifetime. I don’t love the RAM constraints either[1] but picking something which is smaller, faster, and more durable is a very defensible engineering call and I think portraying that as a cynical cash grab is more intellectually lazy than we should expect around here. Notice how the person I replied to has been unable to engage with this at all beyond cheap shots which are indistinguishable from the posts you’d have found in some PC vs. Mac thread 3 decades ago.
1. Although I will note that it’s been many years since I used a browser which couldn’t suspend unused tabs.
So imagine it wasn't soldered. Was apple justified back then asking for $200 for another 4gb of DDR3? Absolutely not. The RAM was identical to what you could get from crucial or anyone else. HDD upgrades were the same way. It's just a 2.5" SATA but Apple's pricing suggested they were made of gold. Maybe soldered ram is more justified today, but you'd be ignorant of the history of this company to suggest they aren't simultaneously trying to screw you on upgrades.
There being valid reasons to solder RAM doesn't preclude being annoyed at Apple for charging 3x the market rate to upgrade it with them, I suppose. It'd be a lot less controversial if that were the case IMO.
I wouldn't be surprised. It was common back then to hear on forums to never waste money speccing up the ram on macs, since you can upgrade it yourself for half the price with sticks from crucial. It was always a $200 upgrade even when you were just getting another 4gb of DDR3.
Would add to the other comments that having sockets increases the thickness of the device.
Now you can argue that you wouldn't make this trade-off but for others including myself it is the right decision. For most people, including professionals, RAM is no longer the bottleneck for system performance.
I don't think the Mac Mini's case has gotten any thinner in spite of having soldered RAM. The M1 says it's 3.6cm thick, while my old intel mini is 3cm exactly, in spite of having socketed DIMMs (I upgraded it to 32GB, which was slightly harder than I expected, but manageable).
That's a pretty bold claim, to say that a company had the motivation to purposely make it difficult to repair. What support do you have for that statement?
And what support do you have on your claim that any EU rule has mandated an approach to make something easier to repair that has made Apple (or any other company) change the way they design their hardware?