I don't really care to discuss business because it's simply a topic I don't care about but let's be honest here - if this was the truth like you assert it is, then why was the Bryan SummerSlam 2013 headlined SS a flop?
If the fans LOVED Bryan that much, they would have ordered in droves, no excuses. They didn't, and didn't really get behind him on any of his other rematches.
Batista on the other hand has a track record and upon return popped a surprisingly big rating.
I don't think they've done Big Dave justice by thrusting him straight into the championship race on the biggest show of the year but there's sound reasoning behind the decision, as much as I personally dislike it.