Fran. I agree. That kind of insecurity comes from not knowing what to do, or how to do it. Some basic training in fundamentals and aiming could go a long way toward correcting the problem. And it is irritating to your opponent.
Steve
In some cases, I think you're right. But in more cases than not, I think it may be more deep rooted than not knowing what to do. A player may very well know what to do but due to some personality issue, they are compelled to get up and down or practice stroke more times than necessary. Sometimes it's an ocd issue and other times it's extreme insecurity and constant lack of belief in one's self.
In those cases, I think they either have to be shocked into stopping or to spend a ton of money in therapy.