If one of the platforms breaks Scirra still has a viable product, so the native argument fails against that alone.
And most of those other platforms can probably do screen capture.
Ashley can't fix the issues with Nwjs.
You can't tell Youtubers what software to use, but you can give them something else to record.
The argument of C2 not being professional might carry more weight if I hadn't just saw a youtuber describe Unity as "up and coming".
I think the real solution here would be to get rid of the tubers.