I hate to throw out the golf comparison, but most of the time, the stroke in snooker is the same, just like a golf swing. The location on the cue ball changes, but the action is the same. If you would only look at the back hand of the pros you can't tell whether they played top or screw or a stun shot.
Now according to biomechanics, the largest error in the stroke is from carrying the backwards momentum into the forward stroke, hence most (if not all pro) snooker players have a pause in the backswing. Some players try to go even further and tried to completely eliminate the backswing all together. Dennis Taylor is one of those players who can still get a very good screw shot without pulling the cue back. But I digress...
However, just like in golf, sometimes you have to have an unusual stroke, whether thats a power stun, or a short distance drag, or whatever. So yes, the punch stroke has its place, just like a massee and it is useful to have it in your bag of tricks.
But learn first to get a consistent stroke, where to cue ball travels the same distance every time, then work on your bunker shots and pitching wedges.