It depends on the body of water. Smaller bodies of water with limited public access would require more harvest of predator fish to prevent overpopulation and stunting as well as preventing a decimation of forage populations. Larger bodies of water typically doesn't have issues with stunted fish nor lack of forage but there are exceptions (e.g. invasive species impacting the Great Lakes). I took a look at the NJ freshwater creel and size regulations (http://www.eregulations.com/newjersey/fishing/freshwater/size-season-creel-limits/) and noticed a catch and release season.
My guesses are that either NJ decided that a high population (high catch ratio) of decent (medium) sized bass is preferred over a smaller population of larger sized bass (lower catch ratio)
OR
the amount of predator fish (bass, walleye, pike, muskies, etc.) has begun to impact forage and this is a preventative measure.
With the catch and release season, I'm leaning more towards the latter than former.
With enough forage and space, no harvest is needed to ensure a large population of small, medium and large fish. Of course, New Jersey Division of Fish & Wildlife may have decided new regulations on a whim without research/data. Illinois for example had an absolutely idiotic fishing regulation regarding Yellow Perch (closed season in July after Perch spawned but allowed perch harvest during the spawn ) that finally changed this year http://www.dnr.illinois.gov/news/Pages/IDNRAnnouncesLakeMichiganYellowPerchFishingOpeninJuly.aspx
It depends on management goals - big trophy fish, large population of fish (usually for consistent harvest for consumption), a balanced approach to both? In a pond with the goal of huge bass, harvesting smaller bass is the cheapest way to go but definitely not the only option. You can use pond fish feeders (expensive), create habitat or areas that promote the survival and reproduction of more baitfish (could be expensive), etc.
