Because the alternative is to add literally a few dollars to the bill of materials for the machine, double the memory, and give everyone a better experience. This also means the machine will last longer and likely not end up in a landfill as soon.
$200 to add 8GB of memory is _insane_, and framing it as "consumer choice" is bad when consumers are being gouged so badly. It's literally at least a 20x markup on the wholesale cost. You can buy 8GB of DDR4 at retail for $20 or less.
Yes, and? Apple's wholesale RAM cost is likely even lower than a computer with socketed RAM, due to economies of scale and fewer parts overall (RAM soldered directly vs. RAM on a separate PCB, plus a socket soldered to the main board).
You seem to believe that doubling (or quadrupling as suggested elsewhere) the installed DRAM has no energy cost. Adding several watts of mandatory 24x7 idle power consumption to a machine mostly celebrated for its energy efficiency seems odd.
My understanding is that at least for the lower-end machines, there are no additional DRAM chips in the 8GB vs. 16GB machines, they just use chips that have double the density, so the power consumption remains the same.
Even if I'm completely wrong on the above, I seriously doubt that adding 8GB of memory to a machine that consumes 7W at idle in total[1] would add "several watts of mandatory 24x7 idle power consumption."
$200 to add 8GB of memory is _insane_, and framing it as "consumer choice" is bad when consumers are being gouged so badly. It's literally at least a 20x markup on the wholesale cost. You can buy 8GB of DDR4 at retail for $20 or less.