I hear you. And I think I understand where you're coming from. But I'm in a different place. And I suspect others (not just the technically naive) are too.
On the RAM I've gone with 4GB and fully intend to upgrade to 16GB myself because, for me, that makes sense.
I've chosen for Apple to upgrade the SSD because of the potential warranty issues of changing it myself, chance that I'll damage the internals (as some have on this forum) and potential issues with TRIM support. For me the extra I pay Apple over the raw component cost is worth it to mitigate these risks. When I was a bit younger I happily built PCs and would have enjoyed doing this, but now the cost of time and the potential hassles are just not worth it to me.
Likewise I've gone for the top processor. Honestly, for my current use, the dual core probably would have been sufficient. But then if we're talking sufficiency (and frugality) I would have bought a cheap PC. I had a budget to spend on a new machine and I've happily spent that. And I can still afford to take my gf out for a nice dinner