Following his side's 10-8 victory over London Irish in Group C of the EDF Energy Cup, former international Richards spoke out over the comments directed at Ashton from Lawrence Dallaglio and Mike Catt in serialisations of their books in Sunday newspapers.
Richards explained: "I find it very disturbing that players are coming out and slating Brian.
"I think it's absolutely disgraceful. These guys should never play for England again.
"Everybody has reasons on occasion to criticise coaches but the unwritten rule in rugby is that you don't criticise each other in the press. It's an absolute disgrace.
"You've got a coach who's taken you into the World Cup final and there may have been a certain amount of discord, but you'd have taken that this time last year."