That said, the big issue is that we don't (yet) get to share Electron installs. If all desktop applications had to bundle all their dependencies, including what the OS already provides to them, they would be just as big.
Electron apps themselves aren't that big. Even Atom.
Actually, I tried fixing that problem with `asv`: https://news.ycombinator.com/item?id=10244073
For example, the only time I've maintained a proficiency in both a webdev stack and a native kit was when I was paid to work on both full-time.
Node's main appeal to me is a similar consolidation: using one language. At least until I find out I'm immortal.
Regarding size, it appears to be around 100 MB, so you could have 20971 separate installations of it before filling up a 2 TB drive.
Memory usage could be an issue, but whether that matters will depend on your audience the app. In this case, the aim is toward HN, so it doesn't seem like an issue.
[ed: Not directed at op, as such, just how silly the general node ecosystem is currently]