I guess I am not seeing so much of that in Nebraska, although we are talking about a pretty "broad topic" and there will certainly be examples of that.
I believe that the impression of pretty and powerful over structure (in the steers) is really a situation in which the more mature steers seem to come to the top. I feel that the primary reason that these steers don't win as Fat Steers is because they just plain get stale. The State Fair winners are March and April born, and SOME of the stout and powerful calves that come to the top as Prospects are December, January, and February calves. These older steers are really hard to keep fresh for such a long period of time.
The smaller, less mature steers we have don't even leave the barn for the early shows. We typically show our County Fair steers at the early shows because they have to be on schedule to be fat by the end of May. I know that some others up here do the same thing. So the State Fair prospects for the most part are not even at the early shows.
Another factor that I see is the really stout progress steers are often times BIG HAIRED, and are being handled by the best guys in the business. After the early shows are over, the steers go to their owners' homes and the hair comes off...next thing you know that awesome hair isn't there come August.
The steer that won our State Fair last year actually won his first Prospect show in late November, and came back and won as a Fat Steer.
I really don't follow the heifers much, so I am not able to add much to the thread on that side.