Scolari became the second Premier League boss of the day to be dismissed, following on from Tony Adams' exit at Portsmouth earlier on Monday morning.
Chelsea's stalemate with Hull City on Saturday left them in fourth, seven points behind leaders United, but Ferguson still feels the club's board have been hasty in showing the Brazilian the exit door.
He told MUTV: "I am really surprised. It is a shock so soon - he only took the job seven months ago.
"He is a man of great experience; he took Brazil to World Cup winners - and was the obvious choice to replace Avram Grant.
"It is a sign of the times. There is absolutely no patience in the world now."
Ferguson also senses the back pages of British newspapers increasingly help to make managers' positions more precarious.
Volatile"It just seems to be more volatile now. You can't always blame the press - but they play a part," he added.
"The way the tabloids are - competing against the Internet and Sky News - there is sensationalism every time someone has a bad result.
"There was great expectation at Chelsea that they were going to do well this year - and it is only this last month they have had a bad spell.
"The judgment really is only on the last month."