Bowlers are no more athletes than chess players. I once had a teenager tell me that chess was a sport because he was "exercising" his brain.
It seems that some people categorize an activity that requires some skill as a sport just to help out their own ego. Both are games. Same as golf.
Any activity is going burn calories. That doesn't make you an "athlete."
Bowling is something someone does when their spouse/significant other tells them to get off the couch and go do something. Same as mowing the yard.