Wild animals live a hard an precarious life and there is little to nothing we can do to change this. The situation in many places is that there are no hunters and no predators at all. If niether happens in an adequate way, starvation will be the result. Mass round ups may be practical in suburban areas, although very expensive. In rural and semi-rural areas the cost would be prohibitive.
Deer can be very elusive.
One impractial alternative is birth control. I've seen deer who are suffering the slow death of starvation. By comparison, the usually quick and clean kill that comes from a deer hunter is far more humane. People who feel compassion for deer, and for that matter wildlife in general, would do well to understand this. That some hunters are irresponsible is a different subject.