The BBC screened 45 episodes of Monty Python's Flying Circus between 1969-74.
Cleese added: "One of the things that makes me saddest about the way the country has gone since I was young is the BBC. I look back at what was really a magnificent institution that, for economic reasons, has been thinned down and become something very different."
Cleese's criticisms echo those of John Lloyd, the producer of Blackadder and QI. He recently said that comedy is a "disaster in television because so few people know how to do it."
Rehearsals are under way for the 10 "farewell" Python shows, which begin on July 1. Terry Gilliam's comments that he found the lucrative shows "depressing" appears to have stung his fellow Pythons.
Cleese said: "I think Terry finds a lot of life depressing. He's been engaged in a life-long struggle with reality, and I think he's losing."
Eric Idle told the magazine: "Oh, he's such a little arsehole! He's got to be the one that's always more holy than everybody else. I'm sure he'll carry on talking it down, but he's always a bit bitter like that, you know? I mean, how's his film doing? He'll be saying he's the only real artistic one, but that's because he equates artistic success with box office failure."
Extra tickets will be placed on sale on Wednesday for the shows, which initially sold out in seconds. The final three-hour long Monty Python Live (Mostly) will be broadcast on the Gold channel on July 20.
"Yes, that really is going to be the last performance," Cleese said. "All the Pythons now do such jolly different things ... We will all get a bit emotional, probably, but I don't think any of us want to go on working together."
Cleese said his great objection to working with Idle, Michael Palin, Terry Jones and Terry Gilliam was that he "was fed up of being outvoted".
He called scenes from The Meaning Of Life, the final 1983 film made by the original group of six members, including the late Graham Chapman, "very second-rate material".
Money was an incentive for the reunion, Cleese said. "But we're also doing it because we think it's going to be a fun experience. At 74 I welcome these experiences."
- Independent