The point is that they are being shot for nothing more than the pleasure of it - and that is sick.
How do you know this? Have you examined the population data for the various species of animals involved and proved that no hunting is necessary to maintain optimal balance between predators and prey? Do you even have a clue what the optimal ratio between predator and prey populations would be, or what the optimal population levels should be, given the local availability of food, water, etc.?
People like you getting involved in wildlife management on the basis of an emotional response are responsible for more environmental problems and animal cruelty than hunters. Let me cite an example. A few decades ago, cougar hunting was outlawed in California because the treehuggers and animal rights people like you thought it was inhumane and disgusting. As a result, the cougar population mushroomed, and the deer population in California was pretty much wiped out. So the cougars weren't able to hunt in their normal wilderness areas any more due to lack of food, and they began moving int urban areas and snacking on stray dogs and cats, small children, and the occasional jogger/hiker--things they wouldn't usually hunt but were forced to due to the circumstances. When I left California in 2005, there had been a string of attacks on humans, and the wildlife management people were concerned about some endangered species being wiped out by the cougars. I don't know how the debate ever turned out; being California, it wouldn't surprise me if the stupidity is still continuing. But if the cougar population had been managed properly via controlled hunting from the beginning, the deer population wouldn't have been nearly wiped out, and several people wouldn't have become cougar attack victims.
Another example: when I was growing up, I lived in northwestern Wisconsin for a few years. During that time, there was a large spike in the starling population. Huge flocks of tens of thousands of starlings were common to see. If one of them passed through your area and stopped to feed, your driveway (and anything parked outside) could go from blacktop to whitewash overnight. It even affected the population of other bird species, like robins, cardinals, blue jays, etc. After a few months of this, the consensus of the community was that the population needed some serious thinning out--it was more or less a civic duty. So I spent most of my allowance on .22 ammunition, and spent much of my free time wandering the woods near my house shooting starlings with a rifle my dad gave me for Christmas. I don't know how many I killed, but I would guess somewhere in the hundreds. That may sound indiscriminate to you, but I can assure you it was a drop in the bucket compared to the thousands that flew by every day. After a year or two, the starling population went back to normal, (as did the other birds) and I moved on to other activities--thinning the starlings out was no longer necessary.
I haven't hunted in years, mostly because I haven't had the free time. But I have no problem with hunting, even if done primarily for sport, as long as it is controlled to keep populations in optimal balance. Believe it or not, most hunters are conservationists--you can't hunt indefinitely if you go overboard and wipe out the animals you hunt. Hunters have done more work to protect and rebuild habitat for game animals than PETA and and the animal-rights activist crowd.
To reiterate my original point: I'm not going to rush to judgment on the "predator derby" hunt. If there is an overpopulation of predators in the area and they need thinning out, then it's a good thing for the long-term survival of both predator and prey populations. If the participants have fun while doing what needs to be done, I don't care. OTOH, if there isn't an overpopulation of predators, then it's a bad idea. Either way, the squeamishness or revulsion one might have to seeing animals shot with a rifle is irrelevant, and is more likely to cause long-term damage to the ecosystem (by preventing needed culling from taking place) than benefit.