The reduction of the complex trade-off between memory use, CPU, disk, development environment, ease of deployment, and the dozen other variables that go into a choice like picking what toolkit to use to "don't be a dick" is so absurdly simplistic. It's a trade-off - not a single-axis "good or bad" decision.
Moreover, 20 MB of memory usage is going to be an acceptable trade-off for the majority of HN users, who skew webdev, not embedded.
If I look at today's top seller computers in Amazon for my country (France, 6th economic power in the world), the top two models both come with 4G of RAM (a chromebook, and a win10). The windows one will already use ~2gigs just for the OS. That leaves 2 gigs of RAM for your apps.
And that's for computers being sold today - they will still be in use in five years.
It's pretty clear that 2O MB of RAM as baseline memory consumption for a graphical application (we're not talking about a runtime that might be used for a bunch of background processes - that would be an issue) is a non-issue for the vast majority of users of such programs.
But if a browser like chrome already uses 1.5 gigs there will be a big difference between the app that uses 500 (your average electron app) and the app that uses 50 (your average Qt, GTK, ex, fltk... app). One will swap and make the whole system slow, the other not.
Yet if you use all of it, its value is also zero - to every other program on the same computer. Don't be a dick; Use what you need, not all you can.