I disagree almost entirely.
The most important metric is how it sounds on your head. Engineering headphones is a science. Enjoying them is not.
The only practical use I've found for FR graphs is for quickly determining if a headphone is tuned to your tastes. For instance, I'm a basshead, so if I see a headphone with an FR graph that shows lacking bass, I'm not going to look into the headphone further, I already know it's not to my taste. Outside of that simple information, FR graphs are meaningless.