Everyone uses tape, all kinds of tape, it is not a bandaid for a bad fit. Why ? because we are all different and some skin is more sensitive than others. Moist skin, dry skin whatever, we are different. Like I said earlier, we are all striving for the perfect feel and we all have our little trick to accomplish it.
Norm Duke has never been in my shop and I never checked his span to see it its right or wrong, but he has been making a very good living with a bowling ball since he was a teenager so who in their right mind is going to tell him he has a bad fit ?
I drill for folks that their thumb never changes and some do not use tape, while others are always adjusting their thumb based on the climate and number of games bowled. NO, this is not a BAD FIT, just bowlers trying to maintain that perfect feel. Everybody is different.