"I put it down to the game no longer being attractive, it's based on ultra-defence," he said.
"Kids get to their early high school years and turn off it in spades... We don't want it to see [rugby], as one submitter put it, move towards extinction."
However, Bay of Plenty community rugby manager Pat Rae said provinces throughout the country were adapting to buck the declining trend.
Provincial unions had been scrapping junior representative sides like under-13, opting to start developing specialist players in their late teens.
"We're moving away from developing the kids early and all of the strategies are interesting in keeping them engaged in the game," he said.
"Once they start to even themselves out around that 15, 16, 17, age group, that's when we start to identify that talent."
Former All Black captain Ian Kirkpatrick told the Bay of Plenty Times he had serious concerns about how physical the game had become.
Kirkpatrick, who played 39 tests and 74 games for the All Blacks between 1967 and 1977, thought the game had become "ridiculously gladiatorial".
"I don't know if I'd be happy playing the game now and doing what these guys do," he said.
"The present professional game is putting off kids wanting to try and get to that stage because of the attrition rate and the injuries, particularly concussion."
Kirkpatrick thought the breakdown and defence were the main areas where change was needed.
Catley agreed, saying the game had become too much like rugby league in having a defensive line - of 15 men, not 13 - spread across the field.
When rugby was still an amateur sport, Rae said teams would commit around eight forwards to breakdowns but that was no longer the case.
"Now we send two players to a breakdown, leaving 13 players in a backline," Rae said.
"It's awfully difficult to break that defensive line because you've got more players waiting to tackle you."
Catley's group is still taking submissions from the public and will review them before making them to rugby's authorities, along with any proposed changes.
"A lot of good men are out there who have seen the benefit of rugby and don't want the new generations to suffer," Catley said.
The group is headlined by former All Black captains Kirkpatrick, Andy Leslie, Dave Loveridge, Alex Wyllie and Stu Wilson, and includes Earle Kirton, Mark "Cowboy" Shaw and Allan Hewson.