Has there EVER been a more WTF decision than Sheamus winning MITB?  I'm serious, he was the last man anyone would've picked to win. Look at the other options:
With heel champion Rollins you have
– Neville – plucky NXT new-gen babyface who could easily survive a loss in a 20+ min main event
– Kofi – hell the freebird-style New Day MITB would be hilarious and of course he'd lose
– Dolph – see Neville
– Orton – so much main event cred, he would give Rollins a big clean win
– Kane – at least would've sense from a storyline perspective
– Roman – DUH.
Sheamus is fresh off losing to Ryback (!) in the Chamber and splitting a feud with Dolph before a few crappy TV matches with Orton. Nobody cares about him as a heel or face, he's almost X-Pac heat, so you kill the whole concept because him running out will draw groans, not boos.  Can you think of anything that made less sense than this?

​Well, I mean, Damien Sandow won the briefcase that one year, don't forget.  I wouldn't call it the most cuckoo-bananas decision of all time or anything because at least Sheamus is a former champion and Rumble winner and such, but he just doesn't fit into the main event puzzle, like at all.  And as you noted, why have him lose the IC title match to Ryback and then come back and win the case?  Unless they just wanted to swerve everyone because Reigns winning would be too predictable.  But in this case, it's predictable because IT MAKES SENSE.  Sheamus does not.  ​