It's a bit tricky though because you pay for an S2 license, but what does that mean?
If they stopped developing the game today, people might have reason to argue, but say if they dropped the Alpha tag and stopped, that's that then, you've payed for and received 'S2'.
Then when do updates stop, when do they move onto S3 and when do they stop updating S3. I'm sure the devs have the plan worked out as best as possible but it must be a hard model to maintain.
From the small amount of work I've released to the public I found support and updates very time consuming... and to a certain extent tedious. Once the final product is released, support essentially eats time for no return other then maintaining - or even perhaps improving - your reputation for future projects. It'll be interesting to see how this pans out with LFS.
edit: I agree with your last paragraph obsolum.