Interesting that someone urges imagining Trenton to Atlantic City. Thirteen years ago, as part of the River Line mix, NJ-ARP in fact did just that, in cooperation with (sometimes even in concert with) pro-rail forces in Burlington County and within New Jersey Transit.
But, as per our earlier thread on Pennsauken's location, the difficulties involved in swaying anti-rail forces to a pro-rail point of view ... any pro-rail point of view ... vis a vis the intersection of the Atlantic City Line and the (now) River Line called for alternate plans. That's before one waded into the issues (political and real-world) over service to Camden, and/or Philadelphia--much closer and more imaginable (for many) origin/destination targets than (relatively) far-away Atlantic City.
In other words, and not to be too pointed about it: Reality supervened. With that, NJ-ARP played the game as it happened, and in the arena where the game occurred. We think we did well enough. Those who despise (D)LRT, of course, will continue to disagree.