Like it or not, the swerve is a part of wrestling. Though the tactic has gotten a bad rap over the last several years (thanks primarily to Vince Russo), there's really nothing wrong with it, in and of itself. Sometimes, a grand surprise that comes out of nowhere is warranted.
Take, for instance, WrestleMania 31. Brock Lesnar was set to battle Roman Reigns in a match that the live crowd rejected due to the challenger's overbearing presence. At the same time, keeping the title on Brock wasn't really an option due to his part-time schedule. In the end, Seth Rollins cashed in his Money in the Bank briefcase to win the belt himself. No one saw it coming, and that helped make it a success.
Still, there are many who would consider that the exception to the rule. Often, when WWE decides to swerve the fans, the big twist is something that only the storyteller thinks is compelling (take, for instance, when Vince McMahon was revealed as the Higher Power). Even worse, though, is when WWE decides to swerve fans just for the sake of being unpredictable. In cases like those, they damage their own credibility - and condition audiences not to get their hopes up.
That can be catastrophic in the long run.