Edit: Apparently nobody gets what I'm trying to say, so I'll summarize it.
1. Bethesda may want to expand housing further with a Hearthfire type DLC.
2. Housing DLC does not typically do well on PC due to the presence of player mods.
3. Consoles now have player mods.
4. The season pass may be used in part as a way for Bethesda to continue making housing DLC, as it would be part of the season pass.
5. I'm not implying that Bethesda is scummy or using scummy tactics. It's what I would do if I was interested in making DLC that people might initially pass up.
So why do you guys think Bethesda went with a season pass? At first, I thought it was a very odd decision, but thinking about it, it makes more and more sense.
One thing Bethesda has (fairly) consistently done was make housing mods for their bigger games, with the exception of Fallout 3 for some odd reason. However, as I looked at their history, a certain pattern emerged. Oblivion's DLC tried to to cater to players by inundating them with several different downloadable player homes. Fast forward to Skyrim and Hearthfire and we see that the homes were meant to be customizable and usable for any playstyle. It worked...kind of. Now, we can make our own, customizable houses and towns. The sizes seem to be constrained only by the material you can gather in the surrounding area (it was implied that materials were finite and were transferred to a local workbench).
However, if memory serves, these housing mods did abysmally on PC, likely due to the existence of player mods, which consoles now have, as well. So...perhaps Bethesda is doing a season pass in order to "sell" a planned housing DLC?
I'm sure there are a ton of other reasons, but this is something that just occurred to me and I wanted to know what the community thinks. Keep the discussion civil and tell me what you think it might be!