from back when I was a beginning teacher making next to nothing, I worked part time at a Goodyear store, since I grew up working on cars it was an easy above min. wage job.
some of the other tire busters said the same thing, oh that has to be lined up with the valve stem. One day we had the "privilege" of having a Goodyear rep at our store talking the engineering behind some new tires. I had the chance to ask him about that dot, on Goodyear it was usually white at the time, he laughed, and said, "all that dot is, is an inspection mark made at one stage of construction, we do sell balanced tires, we have no idea if your rim is balanced, so how could we mark a tire to match your wheel."
so I totally have to agree with you. Besides, if you truly wanted a good balance, it needs to be balanced on the vehicle so you can balance out everything, including hubs and brake components.