At the risk of being overly philosophical, one of the major issues with anything like this is that they attempt to define a profession based on their own views on it. Even if they were to somehow use a sample of those within the field, it would still be biased by their own preconceived notions of what the field should and should not be, what it is to them at the moment, and how they think society views it.
We have more freedom to define how we practice within our field than I think many people consider. And as you get to know more psychiatrists you'll get to realize that there are a vast array of personalities within the specialty. In my opinion, moreso than others, but that's another story. The fact that such a diverse group all go into a single profession implies that the profession itself is far more flexible and varied in its practice than any survey could ever hope to capture in a meaningful way.
P.s. Psych was 8th for me, PM&R was 4th, Cards was 20th, and primary care stuff was all in the mid 20s. I listed those in my actual order of preference lol