There were some traffic backups this morning, but nothing approaching the level of anarchy and disaster that I'm sure the protestors were hoping for. Perhaps they didn't realize that the city has already been well-versed in Macdonald Bridge closures over the past few years?
It seemed like: "oh, the Macdonald is closed again... OK, let's go to plan B...".
Regarding the police closing the entire bridge, I don't think it's unreasonable, given that they were not allowing the protesters to pass the tolls and actually populate the bridge (perhaps worried about angry protestors trying to permanently damage the bridge so that it would be closed for a longer time?)
It seems to me that if they closed off the span to keep protestors off, but kept bicycle and pedestrian lanes open, it wouldn't take long for the protesters to figure out that they could get onto the span using these access points, and perhaps injure themselves trying to climb fences etc to occupy the vehicle lanes...
Basically, when the bridge is closed, it's closed for everybody. Fair enough.