This is just a Transition device. Because Broadwell is not ready. They could either spend a lot of money to make 2 different motherboards for 6 months with dual and quad chips as they are different or wait and realise a unified broadwell which i suspect will come with a new design and possibly be built in the US.
The other thing of course is they could easily release a Quad core in a month or 2. Perhaps it's just not ready as they had to create a stopgap because Intel delayed broadwell 8 months!
Problem is the new machine will be even more locked in than this, just like every other Mac (except the MP maybe).
Ram ALWAYS fails at the Connectors and blows out. Inconsistent gold coverage Dust/moisture and heat etc. Soldered ram is and has always been much more reliable. Had many ram errors on your tablets or phones recently? Or how about that 4K tv with 8gb ram... Soldered.
All well and true perhaps, but this is more of an outcome rather than a reason to Apple.
I'm gutted. Just wish they'd make one 'hobbyists' machine (kinda like the mythical xMac), to appease folks like us. I believe that we are the tech influencers in our families; lose us and they might lose a lot more.