Season Pass only for some seasons but not others?

I am curious about something and wondered if anyone knew the answer – why do some TV shows have season passes and some require you to buy them a bit at a time? Even more baffling why will TV Show Y, Season X will have a season pass while TV Show Y, Season Z will not. For example the latest Sofia the First season compels you to buy each one individually and come back and check if there are any new episodes while when season 1 and season 2 came out you could buy season passes for both.

Is this something purely driven by the copyright owner (in this case Disney)? Or something to do with Apple and the how it provides season passes?

In either case anyone hazard to guess at any situation where someone like Disney/Apple would choose one option instead of another for the same show? Or even a different show but under the same brand (so Phineas and Ferb has a season pass, but not Sofia the First).

It all seems inconsistently silly.