It’s not a matter of people being mostly right-handed; it’s a matter of being useable by both. The point is that, for anyone other than a bowler with plenty of experience and an approach which might need it, a “pusher” shoe is unnecessary.
I once bowled one ball while wearing street shoes. I ended up flat on my face and boy, was I embarassed. My friends and I couldn’t stop laughing. I will never again roll another bowling ball without wearing bowling shoes.
In addition to the difference in the soles others have noted, most bowling shoes are extremely ugly—not something you’d want to wear outside a bowling alley. I presume they’re made this way to discourage theft.
They would go out of business. Street shoes would ruin the approaches and those things are expensive.
Interestingly, fashion shoes lately have included so-called “bowling shoes.” These are shoes that have the same general appearance of the bowling shoe, and often the same ridiculous coloration. Kids wear them; proving that there isn’t anything that can’t be made fashionable if Madison Avenue is willing to try. 
It is possible for kids’ bowling shoes to just use the “rubber” bottomed slippers they sell at Target.
Or gripping socks? They are for kids, so I don’t want to spend a lot for them to out grow them.
Ballet slippers?
After all this time there is still a question on the difference. The answer is bowling shoes are fugly, to prevent someone with any shoes of their own not to steal them.
Bowling shoes are for zombies.
Hmmm.
For how mu–nevermind; NO! I WOULDN’T RENT A TOOTHBRUSH, NO MATTER HOW LITTLE IT COST!
Does it have one of those soft pointy rubber thin–wait, NO!
Street shoes will destroy the approach to the lanes, which is why they are a bozo no-no. Back when I used house shoes, I never got a pair that stank or was old. Now that I have my own shoes, it’s not something that matters to me any more.