These are my Opinions:
Have I switched from C2 to C3 the Answer is NO. I think having a subscription base for a single individual is a bad idea.
The individual game developers who are paying for content expense has enough to worry about, like Sprites, Backgrounds, and Tile sets ect.
Solutions I think would have been much suited options for Construct 3.
1) Having one time fee for a individual licensed software.
2) Charging a 5% fee if money is made off a published game.
3) Businesses & organizations based on sizes charge subscriptions.
4) Educators, students and institutes who are qualified should be free for innovative purposes only.