I don't think the debate is about 17 vs 11 because the numbers are clear. Federer has achieved more in the primary categories. Nadal has kept pace in the secondary categores.
What secondary categories?
I believe the debate has more to do with how can Federer be the best ever if he loses over 60% of his matches against his main rival. Roger has an excellent record against the rest of the field. Nadal has a great record against the rest of the field, but not as good as Roger. That being said, Rafa still has a better winning percentage.
Professional tennis is played mostly on HC, and yet most of Nadal's wins vs Fed (or anyone else) were on clay.