[ciupicri]

> If StackOverflow does something like put up a paywall and lock it up, then it will die off and some other site will arise that will replace it

As others have already said that possible thanks to their liberal license, not despite of it, so you're wrong, hence the downvotes (though I haven't voted in any way).

[volaski]

As a thought experiment, do you think if StackOverflow changed their license tomorrow (hypothetically because of the spam problem) but assured all its users that they will never mess with them, all users will leave simply because of the license?