What they are calling sneakers may not be the same thing as you. Amazon has two separate categories of athletic and "fashion sneakers" which are not athletic shoes but are the old fashioned canvas sneakers and the like.
Congratulations on nitpicking the one questionable example. Bottom line is, almost every site I looked at said sneakers, and the ones that didn't used something more vague, like athletic shoes (not one of the choices in the surgery apparently). Not to mention that I've yet to find tennis shoes (unless they're actually specialized shoes for tennis) or gym shoes.