We'll ignore the strategic use of bowling shoes and how they help bowlers perform better. That's another issue altogether. For those of you who bowl a couple times a year and don't have your own bowling shoes, you're required to rent some before you bowl. Depending on your mindset, this is either a fun experience or a disgusting bother.
But why do you have to rent them? Are bowling alleys trying to squeeze you for every extra dollar they can? (No.) Do bowling shoes really make a difference? (Yes.)
Maintain the ApproachesOne of the most important pieces of a bowling alley is the approach. This is the part of the lane you walk on prior to releasing your ball. For maximum performance, the approach needs to be flat, moderately slick and free of debris.
Imagine a chewed piece of gum on the approach. You walk up to throw your shot, don't see the gum, step on it, stick when you're expecting to slide and fall on your face. This is why most bowling alleys restrict food and drink to behind the lanes.
Now, imagine if you didn't have to wear bowling shoes. The person who was on the lane before you walked in wearing street shoes that had gum stuck to the bottom. As be bowled, that gum wore off on the approach. When you take over the lane, the approach is sticky and dangerous.
How do Bowling Shoes Help?
Outside of the performance reasons, bowling shoes are strictly worn in bowling alleys. So, as long as no one takes the bowling shoes outside, theoretically, the shoes are clean. They definitely don't look clean, but the soles are far more controlled than if everyone was allowed to walk in off the street with filthy shoes.
Bowling-alley managers are not trying to gouge you out of a couple dollars. They're trying to keep their equipment in top shape while avoiding accidents and averting danger for the customers.
Even when renting bowling shoes, you should avoid going outside in them, especially in the rain or snow. Likewise, you should not wear them into the bathrooms or walk through spilled food or drink anywhere in the bowling alley. If everyone takes care to not track filth all over the approaches, everyone is safer and has more fun.