Why do many BDSM people look down on switches?

[RickBulow74]

As one who had initially brought this topic up in another post, I am liking the feedback from those in the community. Many people feel that being a switch is not natural, even going so far to say that people are either one or the other and there is no middle ground. As I think a few had mentioned here, a sub is not automatically submissive to EVERY single Dom and vice versa. As such it is logical to be a switch in my mind.