Winning could overshadow what parents might actually want their children to learn from sport - whether that be developing leadership skills, learning teamwork, or just having fun.
"The way the sport is focused is very much on winning the game, the focus is on the scoreboard," he said. "The focus moves away from development, from develop their skills and giving everybody game time and all those positive things sport can do."
Shifting the focus from development to winning also meant the behaviours of adults involved in the game could change, where parents would criticise the referee, criticise players, or chastise their own children on the car ride home.
The most likely reason why supporters coached from the sideline was thought to be a lack of understanding about its effects.
Some supporters' perception of sport meant they took certain behaviours for granted, as they did not know any differently.
"When there's somebody yelling at a kid, nobody confronts that parent because that's what sport is, and a lack of awareness for many people is what allows us to let that behavior continue," he said.
"What we're trying to do [through Good Sport] is empower parents to go, 'well actually here's some research which shows that it's not a good way to coach, it's not the best way to parent ... that's not a good experience my kids are having' and actually empower them to bring it up and change it."
While this type of behaviour could ruin a Saturday morning sport game, its effects could actually be far more long-lasting.
"If a kid's moving into an offside position during the game, you're yelling at them to get back, well basically all they're doing is moving back ... there's no real learning taking place there," Dr Walters said.
"So there's a major impact on the long term development of skills and their ability to make decisions."
Unfortunately what children were learning from sideline coaching was a fear of failure.
Research had shown children would act one way if they thought they would be rewarded, and would be scared to do things if they thought they would be told off.
When children did something well during a sport game, "they'll look across to the touch line to where their parents are, looking for some sense of approval".
However, their desire for approval meant when young athletes were developing, "they're actually behaving in a way, they're not experimenting, they're worried about failing. That's the major emotional impact on them and their learning as well."
When asked, Dr Walters said putting pressure on children could be setting them up for failure in their sporting efforts.
The fear of failure, or not being good enough, could lead some children to deliberately not try hard, as they did not want to be ridiculed, Sport Psychology literature had suggested.
"A lot of these kids, their own perception of how good they are is pretty low so therefore they can retain some control over what they do if they're shown to be a little bit lazy or don't try hard," Dr Walters said.
"If you can create an environment that's supportive ... and [kids are] not going to be told off when they make mistakes, they're more likely to try hard."