Their ownership of United provoked much criticism and resulted in the setting up of breakaway fans' club FC United of Manchester and the Green and Gold protest movement.
The Red Knights consortium, a group of wealthy supporters, considered making a takeover bid but put those plans on hold in June.
However, Ferguson believed the Glazers have been unfairly criticised.
"The debt has come through by the club being bought out by an owner. You know full well that when a business is bought it's usually bought with debt," he added.
"Because it's a football club it seems to attract more negative reporting from the media and from the fan but Manchester United Football Club, when it went plc, it was always going to be bought. It was inevitable.
"So when a particular family like the Glazers have bought it, it's unfair they come in for criticism because anybody could have bought it."
Ferguson, 68, is heading into his 24th season in charge at Old Trafford, during which time he has won 11 Premier League titles and the Champions League twice.
There will be a point when I do quit but I have absolutely no idea when that is. I tried that a few years ago and it was an absolute disaster
Sir Alex Ferguson
Chelsea overshadowed United last season by clinching the Premier League and FA Cup double but Ferguson insisted he is as hungry as ever for success and was not even considering retirement.
"Every day, every year there's the challenge of being at the top and that helps me. I think you need good natural energy and I've been blessed with that," he said.
"I'm very fortunate about that so I'll keep going as long as my health keeps going. The same applies to every person. I'm 68 and so far my health has been standing up.
"If I have my health I can carry on. There will be a point when I do quit but I have absolutely no idea when that is.
"I tried that a few years ago and it was an absolute disaster. Agony. My wife made me change my mind and she was dead right.
"I think she was soon fed up with me in the house. Now when the time comes I think the club should be okay."
Meanwhile, United beat the Major League All-Stars 5-2 on their pre-season tour of North America.
Debutant Javier Hernandez, who joined United from Chivas de Guadalajara in May, scored in Wednesday's match.
Darron Gibson and Tom Cleverley joined the Mexico striker on the scoresheet, while Federico Macheda grabbed a double against the cream of Major League Soccer - in front of a crowd of over 70,000 in Houston, Texas.
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