Agreed... they are full of it. Camber can be adjusted. You may not end up totally within spec with a lift, but there is room for adjustment. Caster is a big thing with these vehicles, as most shops don't know what needs to be done to adjust. In order to adjust caster, they need to loosen the lower control arm mount and move that.
For reference, here is the print out from when I had my alignment done after full lift and tires...
