Why are shoes called tennis shoes if they are not for tennis?

Most of the time it just depends. A lot of people call regular sneakers 'tennis shoes', even when they aren't tennis shoes. Tennis shoes could generally be noticed by the tracks or markings on the bottom of the shoe. Most tennis shoes have non-marking soles with a round track under the big toe bone. Rubber Felts are included around the sole and upper shoe, that way toe draggers won't rip their shoe in 3 days