Though Roy has his reasons for feeling the way he does, he should show more respect to his former manager and team-mates.
Roy is being Roy. He never backed down as a player and he is the same now. While others might have buried the hatchet with Sir Alex, he has stuck to his guns.
That's just how he is. He's an abrasive personality who always speaks his mind.
In the dressing room, he would shout at you if he didn't like the colour of your pants. Roy was never wrong, and he would never lose an argument.
But he is not going to win a war of words with Sir Alex, and he risks tarnishing his reputation with United fans.
He is still rightly adored for his performances on the pitch, but I don't think he'll find too many people siding with him now. Maybe he doesn't care.
People have their opinions about Sir Alex. He can be ruthless, no doubt, but when his approach brings you 12 Premier League titles you can hardly complain.
As a direct beneficiary of that, Roy should know. Yes, Sir Alex would not have won without great players like Roy, but time and again he has rebuilt his side over two decades of success.
He has never been reliant on individuals, and has been quick to dispense with those in danger of overshadowing the team - like Roy in 2005.
Roy was wide of the mark with his comments about Sir Alex exerting power over other managers, especially his former players.
What he sees as Sir Alex controlling people is actually just respect for him.
Virtually every player who has featured under Sir Alex respects his achievements and what he has done for their careers. Why should players who go on to manage be any different?
Furthermore, Sir Alex is generous with his help and advice to new managers, and that is where Roy risks looking like a hypocrite.
He was quick to exploit his Old Trafford connection when he was at Sunderland, when he signed the likes of Kieran Richardson, Phil Bardsley and Liam Miller from United and took Jonny Evans and Danny Simpson on loan.
Speaking personally, I know I have been accused of being biased towards Sir Alex and Roy might have something to say about that.
But all I am doing is speaking honestly from the heart, and it would be strange not to have positive feelings about a manager who helped turn me into a Premier League champion.
I respect his achievements, his methods and the way he helped me further myself as a footballer. But Sir Alex has never made any attempt to control me since I left the club. Why would he?
In the past, Roy has criticised former players who have gone on to work in the media, and now he is doing just that.
I wouldn't question his management record, as it is an incredibly difficult job that I would not fancy doing myself. But the way his career has gone suggests that Roy might benefit from showing more humility in future.