Some parents are pushy. But ultimately kids aren't going to become sporting geniuses unless a) they really really want to do it and b) they have some natural talent for it.
I think a lot of parents call other parents "pushy" because they are embarrassed that their kids are not making it and need to come up with some negative reason why other kids are more successful. it can't be that the successful kids are more talented or harder working than their kids, it must be the "negative" way the pushy parents are bringing them up by forcing things on them.So they get to blame other parents for why their kids are not achieving, because the ones that are are hothousing. Maybe easier to do this that to face up to your own kids lack of talent or your own poor parenting.
I had this to a degree at school. I was pretty successful at academic subjects at school but my parents were labelled pushy but they were not really that bad at all and pretty much left me to it. It was just that I was pretty good at lots of things and had natural talent (sport wasn't one of them).