The app looks absolutely awesome, but i would have loved to just see it run in the browser, I'm kinda reluctant to install yet another memory-hog for basic tasks.
So for example, if you want to capture Ctrl+Tab and move to the next note, based on that, well, you can only do that in Electron. Another UX based reason, is that native menus offer a better UX than having to put buttons for each and every action inside the app.
So apart from the usual arguments of cross platform, and we already have JS developers, there are other good reasons to go with Electron.
Also, if you want to do something like display a decently advanced HTML view, WKWebkit might or might not cut it. And it get's updated only when the OS itself get's updated (atleast on older versions of OSX). So if that's the kind of thing you want your application to do, then you pretty much have no option other than Electron.
So use a different key combo? There are plenty to choose from. I use cloud9 and it uses Crtl+[ and Crtl+] to cycle between tabs.
Personally I hope some day chrome comes with an "electron runtime" option built in so I only need the framework once on my PC.
And also easy to close and lose any notifications than running in dock or menu tray.