I truly think it's because of the people on those extreme ends. One side pushes, the other pushes back, and no one wins. We get a bill that says the age limits for purchases, and some guy on one side will add a rider to ban magazines with more than 5 onto it, or on the other side will add a rider for unbanning full on assault rifles. Then nothing gets passed because both of those things are over the top.
One day, DH and I were at the local shooting range. I had to take a class on their rules at the range, as it was my first time there (DH had been there before and had completed it already). The range was running a concealed weapon class that day, and some of the people there should not have had a gun in their hands. One woman had the gun in hand while in line for the class, chatting with her friends (and honey, they were all WASPs if I've ever seen one). She waved that gun around while talking. The sheriff that was there to process the applications for the class walked over to her, removed the gun from her hand and told her she wouldn't be taking the class that day; and that if she wanted that gun back, she needed to talk to the nice deputies at the station house and explain to them why he took her gun away. She had never held a gun before, she said, so she didn't know the rules on it. The sheriff said that is why she didn't need to have the gun or a CC permit that day. The tantrum she threw rivaled those over-tired 2 year olds at WDW. She ended up with cuffs on, for disturbing the peace, and the sheriff shut down the CC class for the day. I just wanted to smack her, but went on to my class, and learned I am right handed, but am a left handed shooter. Interesting.