Moving prey to your planet is just making sure you will win. They cant expect the humans to be worthy opponents when the odds are stacked against them from the start. But of course, they will be worthy opponents even if it doesnt make any sense cause its a movie, and brains must vacate premises whilst viewing.
Any difference to wealthy people going to closed off game reserves and shooting doped up lions, tigers and the like in our recent history?
Not saying this will be the case with the predators, but surely there are lazy fat cat predator businessmen, can't believe they are so advanced without any kind of commerce or economy to drive them