My knee jerk reaction is YES, there are too many, and that I don't like them. Most are full of immature people playing out the lowest vibe possible in that they are hateful, judgmental and / or overbearing. And yes, we all know that is true for some of them.
BUT, there are also good ones that had me hooked. I LOVED Flying Wild Alaska, the story about Era Alaska, and the Tweto family. They are the airline that goes literately where no one else goes, and are a single lifeline for remote areas in Alaska. Talk about fascinating.
I also am a sucker for cooking shows. I know they are probably all fixed in some way, they do seem 'not quite right' in editing, and so forth. But I still love them. Top Chef, Chopped, and The Next Food Network Star and Hell's Kitchen are fun. I also loved the baking cook off by the Cake Boss family.