It bugs me. I know it is nit-picky and pedantic, but it has become one of my pet peeves – because it is an absurd way to use a construction metaphor. You can build on a base. You can build from a base. But it does not make sense to go to the bother of creating or finding a base if you are then going to do the rest of your construction somewhere else (i.e., off of it). If you are going to build “off” a base, why mention the base in the first place?
That is all.