Why?
Just because "everything else has it"? I can see the point in a unibody car, but a vehicle with a frame doesn't need them. When hit in the side, the truck will only deform to where the frame is. That story proves my point, as those models were tested with and without side air bags and there was very little difference in outcome.
Side air bags are just another complexity and maintenance headache. Instead of taking 10 minutes to remove the door panel, now it will take 2 hours carefully following a written procedure to avoid setting off the stupid air bags.
Besides that, the chance of them saving you in an accident is less than the chance that the fireman cutting the truck apart to get you out will hit one of the 6000 psig nitrogen air bag cylinders and kill everyone in a 10 foot radius.