For certain definitions of 'high-end', maybe. You've been able to configure workstation-class laptops with 64 gb for a few years now.

And most mid- high-end laptops will happily accept 32GB, again going back a few years.

(Broadwell removed the density limitation that made 16GB DIMMs a no-go; anything that takes DDR4 should support 16GB SODIMMs, excepting the very low end Atom, Celeron etc.)

Why am I expected to have a workstation-class laptop to run my text editor?

You really aren't. Atom runs fine on a Macbook Air. There are definitely performance issues, but we're addressing them; it's just that our team is small and our initial goal at launch was to produce the most hackable text editor possible.

I had to drop Atom when it began launching white flashes when scrolling on a 2011 MBA. I saw that this was a recurring problem. Is that an issue that is being addressed?

Do you remember if there was an issue opened for this on the Atom repo? I haven't heard of this problem.