Yes, they could also have sent all players a few dollars - just because.
Demos are no longer common. That's sad, but you can't single out one publisher for not doing it. That's unreasonable. They're expensive to develop - and games are getting very, very high budget in the AAA segment. It's not something you do just because some people feel entitled.
Betas are usually more extensive than demos - and they give players a better look at what the final product will be.
Again, they're offering players access to the beta as an incentive - and no one is exploited or forced.