People love to bowl. That's a fact. They have their own lingo, clothing, shoes and tricky scoring methods that lead some to believe they have their own form of addition. Professionals don't have physiques normal people would die for, they don't make a ridiculous amount of money and they don't attract attention from members of the opposite sex who otherwise would be out of their league. The best way to determine the validity of a sport is in the observation of its participants.
Many professional athletes spend their lives running, lifting weights and eating a healthy diet.
But bowlers don't have to. Bowling alleys sell pizza, chili-cheese fries and beer, and bowlers heartily engage in the consumption of these less than healthy foods. Then there's the problem of exposure. Sports fans across the globe recognize Shaquille O'Neal, and Mark McGwire. These athletes are superstars in their respective sports.