The ICC - in order 'to protect the integrity of the Adelaide Test' - fast tracked a hearing into charges that du Plessis had applied mint lacquer to alter the condition of the ball during the second Hobart Test.
Former South African batsman Richards insists focusing on monster bat sizes rather than a ball enhanced with mint-fused saliva would fix an imbalance forcing bowlers to find ways to compete.
"My bat edges were 18 millimetres and David Warner's is 60 and no one says a word. The bats have changed and the ball hasn't. The focus is on the wrong thing," said former MCC Cricket Committee member Richards.
"If there was a 50-50 contest the bowlers wouldn't be looking to do something else, they just want half a chance."
Richards believes the mint-gate reaction has been over the top and detracted from South Africa's landmark series triumph.
Cameras this month appeared to show Indian captain Virat Kohli enhance a ball against England while chewing gum. Richards says no team or players should claim moral high ground when it comes to polishing balls with mint lacquer like du Plessis was charged with.
It's not like this is new with mints or Brylcreem, it's been going on for 50 years," said Richards.
"I would be amazed if Australia weren't doing it. These guys play each other in the Indian Premier League, talk to each other. They must all know about the advantages."
Australian opener David Warner yesterday maintained it was due process for the South African who gets most under Australian skin, du Plessis, to be held accountable for actions on the field.
"If you're going to overstep that mark and you get fined, be prepared to miss Test matches as well," said Warner of du Plessis who made a ton on debut in Adelaide four years ago.
Richards cautioned against scrutinising rivals saying: "I respect David Warner, he is a fantastic player but you can't tell me he hasn't put a foot wrong before."
Richards loves Adelaide and its pink ball Test but says a dead rubber Test would have lost allure if perceived villain du Plessis was absent.
"I think you would lose something as a contest," said Richards of du Plessis, who has superbly marshalled the tourists in the absence of injured, regular skipper AB de Villiers.
"It's disappointing it has got so much profile when it should have been on how well South Africa has played over the past two Tests."
South Africa feels a team under siege despite its success here. Security manager Zunaid Wadee was involved in a physical altercation with a television reporter while zealously shielding du Plessis on arrival at Adelaide Airport on Monday.
