I often see a lot of veterans stomp their feet after hitting the ball.
Why would one want to stomp after hitting the ball?
Is this purely a stylistic issue? Or does it improve ones follow-through?
You can see an example here.
Some players stomp during the serve to hide the sound of the racquet hitting the ball. The sound of the contact can often clue a receiver into the pace and spin of a serve.
Other players merely stomp as a natural motion as they try to impart spin onto the ball.
Although I can't verify this, it could be for balance purposes. I know that in tennis (related sport), when you come into net to hit a volley, good technique states that you should "stomp" with your (assuming a right-handed player) left foot for a forehand volley and stomp with your right foot for a backhand volley because it helps you mentally and physically hit your shot with a firm wrist and be on balance like you need to be.
It is stylistic.
The fact that the people you refer to stomp after they hit the ball shows that it isn't improving anything. Also, research shows (I'll find it for you if I can) that your legs to not effect the way your arms move, so it won't help follow-through. It's all in your head :-)