It stands to reason that the most popular screen recorder will made in such a way that allows it to record a wide array of applications without issue (thus it's popularity).
It's argued that a C3 game compiled with NW.js is equal to Electron in every way, except for seemingly the ability to work with screen recorders.
I think it's logical to conclude that the fault lies with nw.js - the screen recorder works with the vast majority of programs but not nw.js, making nw.js an edge case, but it does work with Electron, which uses the same underlying technology.
It's fair to assume that nw.js either hasn't implemented something correctly, or Electron is going a step further in some way.
EDIT//
Despite all of this, it's more fair to argue that the onus to providing a successful software recording experience lies with the developer of the recording software, not the software being recorded.