It's baffling why someone would do this tbh. It's not like the base project is some spectacular piece of engineering that would be very costly to replicate.
I'm guessing they just looked at it as a jumping point. It probably went something like:
- We know how to polish an electron app
- here is a barebone electron app with an interesting idea
- Can we build a polished UI around this, and give a demo?
The baffling part is, had they just disclosed that, no one would have given a shit. Plenty of demos begin like that: "here is a cool idea we found, here is that idea on crack". is a very common demo pattern. But of course you can't give a shout out to 'cheating-daddy' at YC demo.
It's like a fine student at a fine college, in a class they are doing fine in, then they decide to copy their friend's cover letter because "eh", then they get caught and now what? wtf would you do this?