I enjoy watching Dual Survival, also Man, Woman, Wild, and Survivorman. I like seeing the things they do, recognizing they don't really "teach" how to do anything, but simply demonstrate a few things that are possible. It's entertaining, not training.
Even Man v. Wild has it's moments, even if only to show what NOT to do.
It's important to remember that most of what's done on these shows is not the idea or even preference of the host(s), but stuff the producers and directors came up with from who knows where and tell the host to do on the show. It has little to do with what the hosts would do in their own training courses, let alone what they would do in a real survival situation.
I do notice that on Dual Survival that when anything important needs to be done, like make a fire, build a shelter, get water, etc., that Cody Lundin does it, while Dave Canterberry goes off wandering around "hunting", most often unproductively. Don't know why that is, perhaps it's just the way the script is written.
Of course, Ruth on MWW is easy to watch, but I can't stand her whiney voice.
I look at the negative stuff on these shows as more an indication of the gross lack of knowledge or skills of the producers/directors and other "big wigs", rather than a reflection of the ability of the hosts. Prior to his passing, Ron Hood posted on the Hoodlums forum that he knew Bear Grylls personally and respected BG's skill and ability in the woods, and admired him for finding a way to make a living using what skills he had gained. Yeah, surprised me, too.
I prefer to get to know what these folks are really like, their ability, background, accomplishments, etc. in their own right, regardless of what's on the TV shows, before forming any opinions.
Just my $.02 FWIW.