I think some people are trying to say you're locked out of your project entirely. That's not the case. You mainly have edit and export access taken away.
As I've said before, we're looking in to adding a special option for people who have had exported projects in the past, so they won't have to sign up for another full year just to export again or make a few quick changes. Assuming we have something like that in place, I don't think it's fair to say any work is "held hostage" either.
That should ease users who want to patch, tinker old projects. I'm looking forward what you'll come up with.
So what's stopping them from still using C2 then? Nobody is forcing anyone to buy C3. C2 would be the equivalent of CS6. And C3 would be the equivalent of CC. C2 is still a viable option for people who don't want to pay subscriptions. Why do you have to use C3? If someone really need or want the features in c3 why not just pay up if they feel it's worth it, if not stick with c2.
I agree with your argument. But I think the main problem here is that serious developers want to have full control over their project. And Scirra needs those serious developers to keep the engine rising. I'll hope the solution Ashley posted above will solve this issue.