I don't agree with you that pitchers are not strong believers in catchers' game calling skills. Of course, I don't have a stat to prove that, so you may be right. But I still disagree, based on everything that I've seen and heard.
I know that the pitcher ultimately makes the decision on what pitch to throw. But one of the jobs of the catcher is to get to know his pitchers well enough to know what they want to throw in certain situations, and to know what is working for them in specific instances. It's not about being able to follow the game plan, but being able to make the correct in game adjustments. You need your catcher to be in sync with the pitcher. You want to the pitcher to have enough trust in the catcher to just take the sign and pitch. Having a pitcher doing too much thinking on the mound or too much shaking off is usually detrimental to the pitcher.
That said, when it comes to the "intangibles", IMO, a pitcher who has his A+ stuff working on a given day could pitch to me and do well. A pitcher who just doesn't have anything working on a given day could pitch to the greatest defensive catcher there is, and it probably wouldn't help. It's for all of those times in between, which is the majority of the time, that a good "game caller" is going to have the most positive effect on his pitchers.