I've been tempted to try making them at home since about 2007, but for some reason all the different people I've lived with since then have objected to me running a lightly modified microwave oven continuously for a month at a time, with a few holes in the heating cavity so I can install an inverted pyrex bowl and pipes to connect it to a low-pressure methane supply system…
I mean, sort of? The median woman who wants the gorgeous diamond ring from her husband is NOT thinking “This will be great insurance in case we become destitute”. Because everyone knows the resell value is terrible! Worst return on an insurance policy ever.
They want them because they are pretty and because – like it or not – it’s what society has taught them to expect.