It's 18 months since he was axed by QPR following the arrival of owner Tony Fernandes.
Warnock told the London Evening Standard: "Tony and the owners had their own ideas so you can't blame them for that - I just think they lost the soul of the club when I left. It became a club for mercenaries.
"I felt the staff and me did a miracle job to just keep them in the Championship and then, to get a promotion-winning team. I deserved more loyalty.
"But there were certain individuals who became too influential on pushing managers' names forward, players' names forward and the board got sucked into spending a lot of money they didn't have to.
"To have the carpet whisked away from under my legs was very unfair. In hindsight, they have wasted a lot of money and got nothing out of it. They've not got any better and are using my players rather than some of the millionaires.
"What happened was the most disappointing thing to happen to me in my career, more so than the way Sheffield United were relegated."