The answer is easy. The majority of people who watch T.V. prefer to sit on the coach and do nothing. So viewing something which is useless is good because these people are useless. Seeing motorcycles that are raced, ridden offroad, or touring adventures would not appeal to them.
I'll admit that I watched the first couple of shows because I actually thought, and still do, that those paint jobs are works of art. I'm not sure I would ever want to ride one of those bikes even for a few miles. I've got back trouble and the lack of suspension would painful to say the least.
I prefer the sound track that my Ducati ST3 makes and the sites my eyes behold as I travel down a 2-lane road. I actually feel sorry for folks who think they're alive sitting in front of a T.V.