You are denying the obvious if you deny that, other things equal the IS rating produces higher values than the other ratings.
That is completely disanalogous, given that there are two jump shooting ratings
(moreover: JR and IS are not parallel at all: the impact of JR on salaries makes me believe that it wasn't meant to be trained as high as IS).
A better analogy would be something like JS arund 14 and JR around 11 which gives roughly proficient ratings.
Why is it a better analogy? Because it roughly correlates (modulo matchup issues) to the same scoring effectiveness relative to a fixed level of defense.
People are confused by the fact that the IS ratings can be so high and yet so ineffective. They assume that if you have an IS rating of sensational/tremendous versus a strong ID you're certainly going to win against an outside offense that does proficient OS versus a strong OD. This is obviously not the case. Possible Objection: some people will get confused.Reply: many people are confused by the current rating.