There was much debate about making it the 1, the 1-and-a-half or the 2. The feeling about putting it on the 1 was that it could turn into too much of a scrum/push-the-pile play, or a fluky puncture-the-goal-line-with-the-ball-and-bring-it-back play by the quarterback.
This is a strange concern. If the types of plays PK mentions here were such sure things, then they'd be used far more often when teams have a yard to gain. Just put it at the one, and give teams the option of kicking for one or going for two. There's something gimmicky about using multiple lines of scrimmage or putting it at the 1.5-yard line.