Well, at least the season pass folks got their money back, which was "the right thing" to do and more than I would have expected either Nintendo or WB to do. *shrugs*  Still, this is kind of what you get for buying what was already a known gimped version of the game right at the outset just because it was $10 less and on a platform with no 3rd party support.
"What you get?" Pretty harsh words.
Dude, I'm sorry but WB showed with Injustice that they would pull DLC from the Wii U version of their games if they felt the demand wasn't high enough.  They cut the tacked-on multiplayer mode 
from the Wii U version of Arkham Origins explicitly 
because the Wii U's userbase is so small.  The warning signs were all there.
I kind of feel with that information if you bought the Wii U version of Arkham Origins 
and then paid WB $20 for the 
promise of future DLC support 
someday, you kind of deserved to get fleeced. Luckily for you, they refunded your money and you merely paid $50 for a mediocre Arkham game, but it's 
always been "Buyer Beware" on Season Passes (even on the other consoles) and Wii U devs have shown a reluctance to bring DLC to Wii U versions of their games.  At some point here, the buyer takes on 
some responsibility for using their money wisely.