"It is not starting again from the beginning, it is going backwards," said Stoner, referring to the arrival of the production-based CRTs and consideration given to a more production-based future.
"For me it is not the championship I fell in love in. It is not the championship I always wanted to race in and, except for my competitors around me, they are the only ones who give respect for each other.
"Nobody else has enough respect for the people that do their jobs, working at the teams, working in the trucks, and putting this show on every week. It is not easy.
"There are many, many different reasons but it is basically me losing my patience with the racing and my enjoyment of this sport. For sure I am going to enjoy this year but if I continue [beyond that] it will be a mistake on my half. It would not be correct to Honda and everyone at the team if I did not give 110 per cent."
"My passion has slowly ebbed away from this championship," said the Australian, who also expressed frustration at the cynicism that greeted his lactose intolerance problems that kept him away from some races in 2009.
"You yourselves, the media, have not exactly been friendly to this championship and criticized me many times, especially recently.
"But people don't realize that everybody is bringing it down themselves, they are saying the racing is boring, that is boring – but if you go back some years you will find the same number of races that were close or not.
"I think people just need to appreciate what they have in front of them, and I think everybody in this room needs to realize what sort of championship they have, before it is gone.
"I think it will be really nice to see some fantastic racing again at the front. But, with only a few factory bikes out there, it is not going to happen soon.
"There needs to be more high quality bikes out there so people like Randy [de Puniet] can run where he deserves to be and not so far behind 12th position. There is no way for them to get anywhere near the factory bikes."
05/17/12 Casey Stoner's Honda team has announced via Twitter that the two-time MotoGP champion will retire from the sport at the end of the current season. The Australian had denied speculation about his exit from the sport in the previous race.
"Everyone seems quite good at stories and making them up," said Stoner at Estoril earlier this month. "I've said many times in the past that my career's not going to go on much longer, I'm not going to keep going and riding until I'm in my 30s and things like this.
"For me at the moment, I haven't decided what I'm going to be doing, and certainly no one else is going to know what I'm doing."
His Honda team confirmed on Thursday via Twitter, however, that this will be Stoner's last season in MotoGP.
"Casey just announced that 2012 will be his final year in the MotoGP Championship. Let's hope he has a fantastic year," Honda said. More at Racer.com