First of all, I usaully think of club calves as something very different from say a purebred shorthorn show animal. They are prepped and presented the same way, but the similarity ends there. Club cattle are usually built from a mix of breeds, so as Muddy said, EPDs, heteritosis and predicatability are out the window. They are a crapshoot, some win, some don't. Honestly, many club breeders know what they have and are dealing with. Most are happy if they get one stellar calf out of the whole crop that makes a state fair steer.
As far as purebreds in the showring, there is a lot of misconception about these cattle and the people who own and breed them. Many breeders will not touch a carrier of known defects. Many breed for functional cattle, and manage to tie that in a nice enough looking package to show. My family has prepped for sale and show cattle of several breeds (Hereford, Angus, Charolais, Shorthorn, Club calves, ect.) and there were true good cattle who had the phenotype as well. We try to breed good functional cattle, but if they break the bank, its pointless. And if they can't stand some competion in the ring, that says something as well. Phenotype isn't the only tool for selecting cattle, but it has to be part of it. There are some judges out there who can see beyond the fluff and puff and really evaluate an animal. Kirk Stierwalt just judged steers and females at world beef expo over the weekend. It is safe to say, steers/ club cattle are his bread and butter, but the man sure does a great job on the purebred females as well.
There is a disconect between show and commercial type cattle most breeds, some WAY more than others. That doesn't mean that there is no place for those show cattle. In the end, breed what makes you happy and is profitable for you. :2cents: