I occasionally go hunting, a semi-auto is simply overkill.
Sometimes its overkill, and sometimes its the right tool for the job.
If your trophy hunting, or popping off rabbits for fun, its definitely not necessary.
However if your trying to eradicate pests at a rapid rate, its a better option than a bolt action for simple efficiency. You can jump on Youtube and see guys driving through their fields in Texas killing dozens of hogs in the space of 5 or 10 minutes at close range. That's just not possible with a bolt action. And if your livelihood depends on getting these pigs off your farm, then you will reach for the semi every time.
I'm a pretty avid hunter, and i have never felt the need to have a semi auto for any hunting i have personally done. But different tools for different jobs.