Interesting. You might be right. The whole "does x taste the same to me as it does to you" question is fascinating, and I hadn't thought about it here. For me, jarred garlic lacks a bit of the bite and spice of fresh garlic, and tends to be weaker after cooking, but I don't associate it with any sour flavor. Basically, it's "rounded-off" garlic to me.
Now I'm curious how you experience powdered garlic. That tastes even less strong to me than jarred, and maybe slightly processed, but I wonder if that has a stronger effect on your palate.