"There was often a feeling that without ‘concrete evidence’ or a specific allegation from a child nothing could, or should, be done", said the chief investigator.
An independent inquiry found that the English Football Association (FA), as well as eight affiliate clubs, didn't do enough to protect children from pedophile coaches.
The report, which was commissioned by the FA itself, says there were at least 692 victims of child abuse between 1970 and 2005, as well as 240 suspects.
Top investigator Attorney Clive Sheldon said that the FA "acted too slowly" in developing "child protection arrangements" once the organisation became aware of such a "problem within the sport".
"Warning signs were often missed or not acted upon", usually because of "ignorance or naivety", he stated. No evidence of cover-ups was found.
Sheldon said that although child protection in sport improved since 2005, he was making 13 recommendations - specifically for the FA - to now act on.
They include assigning one FA board member the role of children’s "safeguarding champion", as well as developing a five-year strategy "with interventions to support the voices of children", and publishing an annual safeguarding report.
FA head Mark Bullingham commented on the findings on Wednesday, saying it was a "dark day for the beautiful game".
Issuing a televised apology to the survivors he stressed that “no child should ever have experienced" those abuses.
“There are consistent features in this review", he added. "Of bystanders who didn’t do anything. Of children that weren’t believed. Of the damage that has been caused."
Watch more on this story from our UK correspondent Tadhg Enright in the above player.