I did my Masters with a concentration in forensics and I don't think it was a gimmick. Could I have had the same experience without going to that specific program? Yes, but having a forensic concentration on my CV has definitely helped me get some great jobs. At my school the concentration meant you would do your practicum or internship in a forensic placement and you can do your electives in the law school as well as participate in research with professors in that area. I think the idea of "I know people in the forensic field who didn't do that and look how well they turned out" argument is ... well, 1. of course anyone can eventually get a good job in a field they want to work in, so no- you don't *need* a concentration or specialty, but it can make things a bit easier, and 2. I think it will become more popular as time goes by, I'm not sure how new these accredited concentrations are, but I'm going to guess they weren't around 10-20 years ago. Also- if that's your area of interest- why not do it? If you wanted to study cognitive psych, wouldn't you look at school that had a cognitive concentration? Of the people I currently work with, most had some sort of forensic clinical experience while in their doctorate program, and did their dissertation on a forensic topic and/or did a forensic post-doc.
That all being said- yes I think MANY people don't understand what it is and some programs are taking advantage of that. [When I tell people what my degree is in I often get "Oh! So you like work in crime scenes and with dead bodies?"] As many people have said- for a quality program it needs to be 1. a general clinical curriculum with just forensic experiences [not all of them, but some] and forensic research, and 2. it needs to be accredited. Forensics is one of the fields where accreditation matters most.
To add to your list of Fordham and Nebraska- U Houston and Drexel have forensic concentrations and are APA accredited and funded. Some other schools don't have an official concentration but have faculty doing research.