From my experience and observation, when a person's computer feels sluggish they either ask someone they know personally (me) why or ask Geek Squad or an Apple Genius. Usually the answer is to simply upgrade the RAM (or have someone switch it to an SSD).
If the Mac Mini is supposed to be a gateway for PC owners to switch to Mac, they're not going to like it when the answer becomes "get a new computer, this Mac can't be upgraded". General non-techy consumers buy PCs mostly because they are cheap. I'm sure they'll enjoy being told that if they had a PC still, they could have upgraded it, but now they have to buy a new Mac which is also more expensive than they're used to.
So the argument that regular consumers don't care about soldered RAM doesn't hold water IMO.
This is besides the fact that Apple knows the Mac Mini is used for more than entry-level computing for first-time Mac users. They offered a model specifically aimed at running it as a small server. Naturally they wanted (and got) quad-core CPUs and upgraded their own RAM as needed.
Apple has simply decided that they no longer care about these segments of their market.
And you wonder why the PC mfg can't make any money. HP, Dell, Lenovo, ASUS, Acer, etc. are basically running their PC divisions at a loss, or no more than 6% Net Profit margin. Welcome to the modern computer industry.
Look at these major players.
HP has been trying to dump their PC division but no takers.
IBM sold off their not profitable PC business to Lenovo.
Compaq sold off their not profitable PC business to HP.
Dell went private.
Acer has gone through 3 CEOs within 6 months due to lack of profits.
NEC got out of the PC industry.
Gateway computer got sold off.
AST computer sold off to Samsung.
Google sold/ or is in the process of selling Motorola to Lenovo at a HUGE loss.
Microsof is laying off thousands of people, they dropped the Surface RT, they dropped the Zune media players, they aren't making money on hardware, they are shutting down R&D labs
Sun got sold off to Oracle.
Lenovo isn't making any profit to speak of. Look at their financials. They are running on SLIM margins and might not last much longer at the rate they are going. They are almost running their business like a non-profit company.
The problem is that the grass isn't greener in the PC world. It's in a downward spiral and the biggest problem I see is that in order for these PC companies to get any sales, they have to make ultra cheap products using i3 processors, cheap plastic cases, and they end up having less customer satisfaction ratings.
Why do you think Apple's Mac Business is still steadily growing and the PC businesses are slowing declining? It's all about customer satisfaction.
With all of the problems I've had on both Windows and Mac platforms combined, I have had far more success with Apple than with Microsoft platform and I've been using computers since 1977 and have used C/PM, DOS, Windows, Macs, etc. and have probably used far more brands of computers than your average consumer. I remember when they would actually replace the actual RAM chip because they weren't soldered onto the mother baord, or replacing a read/write head on a floppy drive, or being able to test a floppy and recalibrate it. times are changing to a more throw it away mentality. That's why we are having everything backed up to the Cloud. if our entire data is constantly backed up to the cloud, we can change the computer, redownload all of our data and then we don't have to worry about the product getting serviced.
I remember when the average computer system cost $5000. The average price of a fully assembled computer is more like half of that or even less. Everything is surface mounted parts rather than socketed or parts that had pins holding them on to the motherboards. Things are made differently now and people want smaller boxes and they have to cut costs to maintain a price point and still be profitable.
The old way of thinking about how computers are designed, serviced, upgraded isn't profitable for the companies anymore. Sorry, but that's the industry.