The Australian typically pulled no punches on Wednesday, explaining why he had not picked any university players among his 30 for Tests against Romania and Georgia.
"We only have a short preparation and the level of rugby they are playing makes it impossible for them to play Test-match rugby by November 10," Jones said.
"I watched a university game at the weekend and it was like I was in a time warp. I thought I was in the 1950s," he added.
"I have to be honest, it's just not rugby. I don't know what they do in training but they have got to change."
Japan take on Romania on November 10 before facing Georgia seven days later, followed by matches against a Basque select side and a French Barbarians side.
England World Cup winner Jonny Wilkinson, currently playing for Toulon, could feature in Japan's tour-ending game.
"The tour is an important step for us going forward," said Jones. "The two Tests will be very physical. The majority of the Romanian and Georgian players play in the French league.
"If you watch that league they play test rugby every week."
Jones named four uncapped players in the squad, while deciding to bring back several battle-hardened veterans such as Hirotoki Onozawa, Hitoshi Ono and Takashi Kikutani.
"We picked the top 30 players," said Jones.
"Last spring our first squad had 302 caps. This squad has 556. If we are to be a top 10 nation by 2015 we need a starting XV with 500-550 caps.
"That means every player has 30 to 40 caps and is able to think under pressure, to play under pressure and to win under pressure."
Jones took a swipe at players who had failed to impress, noting one of the requirements for selection in the pack was the ability to drive players backwards.
"(Suntory Sungoliath flanker) George Smith runs around like he's got spiders on him because no one wants to tackle him," said an exasperated Jones.
"He should be an inspiration to every back-row forward in Japan. He's the same size but he has the highest work rate. But no one ever hits him.
"You need to see that attitude of 'I'm going to smash him' if you want to make a mark in world rugby. Kikutani is the only Japanese player who is doing that."