Shane Warne says Australian cricket is struggling and needs to return to its grassroots foundations.

The spin-bowler criticised Cricket Australia for "devaluing" Sheffield Shield cricket and said the organisation needed to earn the respect of the public again after the ball-tampering scandal that ended the captaincy of Steve Smith.

"I think we're struggling, [we're] pretty ordinary at the moment with Australian cricket," Warne told 7.30.

"I think in any business you need the foundation to be strong, and the foundation of Australian cricket has always been grassroots cricket, club cricket, and first class cricket, Sheffield Shield cricket.

"I don't think there's enough first class cricketers getting into school cricket and inspiring people and talking to young boys and girls to say cricket's a great game and this is why, teaching them techniques.

"Yes, they're busy … but you've got to find time and you have to find a way to make sure that school programs have opportunities for boys and girls.

"I remember growing up and all those school programs I had were great, and the state cricketers would come down and see us and you'd go, 'Oh wow, that's Simon O'Donnell' or 'that's Dean Jones and that's Merv Hughes'.

"It just doesn't happen anymore."

Warne said he would like to see first class cricketers playing club cricket and international players playing Shield cricket.

"They've got to do it, just have to do it for the longevity and success of Test cricket in Australia and for Australian cricket to remain strong," he said.

"I think Cricket Australia at the moment are devaluing Shield cricket, and the reason I say that is, some players are playing one innings of the game, they'll bowl for 10 or 15 overs and they'll say, 'That's it, stop now,' pull them out of a game and just let someone else play."

'I thought they were very hard done by'

Steve Smith breaks down at a press conference in March where he apologised for his role in the ball-tampering scandal. ( AAP: Brendan Esposito )

Warne said all Australians "were disappointed, we were embarrassed" about the ball-tampering scandal.

"I think the wider cricket community thought, 'Australians don't do that, that's not the way Australians play their sport. They play it hard, they play it tough, they're uncompromising, but they're fair'," he said.

"So it was really disappointing to see that. They have to earn the respect back of the cricketing public, and Australian public, and all the cricket community."

Warne said he was no longer close enough to the game to say whether the current culture of the sport was partly to blame for the incident.

"I will say this about Steve Smith. Steve Smith is a good person, he made a silly mistake, and an error in judgment. I think we're, in this country, sometimes too quick to hang people," he said.

"I don't think the punishment fitted the crime. A 12-month ban for that equated to about an $8-$10 million fine.

"I thought they were very, very hard done by and it was a very harsh penalty.

"But having said that, we hated it, and we didn't like it, and they have to earn our respect back."