The 1st pitch changeup

In baseball circles it's widely recognized that you don't throw a 1st pitch changeup. Is this outdated dogma or does it have some merit?

The reasoning is that the changeup is effective when the batter knows what the fastball actually looks like. If the first ball that is thrown is the changeup then the batter isn't fooled by the change of speed. Rather than the batter being out in front of a change he would be more on time because he wouldn't be geared up for the fastball.

I don't agree with this thinking. I think the changeup is effective because the batter is anticipating the fastball and swings based upon what he perceives the speed to be. A batter can certainly have a pre-conceived idea about a pitchers fastball without having seen it for one at bat. A pitcher can throw up to 100 and some pitches throughout the course of the game. I think it would go to reason that a batter might have an idea what a pitchers fastball would look like without having to see it during the course of an at bat.

Furthermore, when you think about what counts batter look for fastballs in the 0-0 count certainly ranks right up there with any other. Why not throw a change up in a traditional fastball count?

To me, a changeup should not be dismissed so quickly as a first pitch option.