I was over in the MacRumors message forums recently, where a big debate broke out about the hardware specs. It seems like a whole lot of "Mac faithful" believe it's about "more consumer choice" for Apple to offer these lower-spec options.
I strongly disagree. From the perspective of someone who has done I.T. support for decades? It's a disservice to customers to sell computers that are gimped by a lack of system resources. Sure, you can find all these use-cases where "8GB is enough RAM" or where a "128GB SSD is enough mass storage". So what? Bottom line is, the consumer just paid a good chunk of change for a computer that should be able to handle a large number of tasks that it's crippled at performing, simply due to the resource constraints. That not only limits its resale value for the original buyer, but often forces them to upgrade needlessly early if their needs change and they find themselves wanting to do something new with the computer.
Another thing I've observed with the Macs with less RAM is, they'll do an "okay" job running some applications, only because the SSD is fast -- but the OS is doing a lot of disk swapping at that point. That means they're putting a lot of premature wear on it, and it's usually soldered in on the Macs. So if it dies, that means the computer is going to need to be sent in someplace for service (likely a whole new logic board).
With Apple already charging a premium price for their computers? They really should equip all of them with at least 16GB of RAM and a 512GB SSD. Better to have that and not need it, than to need it and not have it.