One of the advantages of running in 3rd in long is that we could break off big plays if someone misses an assignment with a 3O.
Another is we did it well.
I don't know what our ceiling on pass pro was, but I know we worked on it at the start of each spring and fall, and then we put it on the back burner. If you want to pass pro well, you need reps. You need backs and (tight) ends that will chip. I don't think we were ever going to dedicate the practice resources we needed to be good at pass pro. So we might as well have shown run.
We should be more balanced moving forward, but game theory would prove to you that you should sometimes run on third and long, just like game theory told us we should have sometimes passed in any situation.