Piquet is said to have deliberately crashed to allow team-mate Fernando Alonso the benefit of safety-car conditions which saw him take the race win, charges which Renault will not contest.
The squad's fate will be decided at an FIA World Motor Sport Council hearing in Paris on Monday.
"I think it's appalling what he (Piquet) did: I can't believe he did it and I can't believe he opened his mouth about it," Moss, who recently turned 80, told Eurosport.
"I don't think it had anything to do with Alonso; I'm just staggered at Piquet for doing it and for coming out and talking about it. I would think he is finished in F1.
"I can't think that anyone would be stupid enough to give him a drive now. He might go to America for the IRL.
"I've lost respect for him… this is all very bad for the sport." Yahoo! Sports