The singer, who rose to fame on Pop Idol 20 years ago, said the way the TV talent show format evolved since then made him “really sad and actually quite angry”.
Will triumphed over rival Gareth Gates on the first series of Pop Idol in 2002, which is widely credited with reinventing the format that has dominated TV schedules since.
His comments come after ITV announced in July that it was resting The X Factor for at least five years following falling ratings.
The Leave Right Now singer told the PA news agency: “It just makes me really sad and actually quite angry.
“I feel a bit unsure as to why a show like X Factor hasn’t had its comeuppance in terms of how it has treated people. And I am surprised.
“There is obviously stuff going on in the background, but hopefully one day it will come out. I wish it was my story to tell but it’s not, unfortunately.
“We were very lucky [on Pop Idol] and I think one of the best things is it was so pure. It was a singing competition and the public were never duped. They paid money by phoning in. They were the record company and they voted for me to have a record contract.
“They took the power away from the fat cats at the record companies and I will never forget that. They were the ones that gave me a record deal.”
Will said standing up to Simon Cowell on Pop Idol, where the music mogul was a judge, had been the “defining moment” of his career.
The show saw the music mogul describe one of Will’s performances as “distinctly average” before the budding performer, then in his early 20s, hit back.
He accused Simon of only “projecting insults” and added: “I don’t think you could ever call that average. But it is your opinion and I respect that.”
Will told PA: “I have to remind myself how young I was and how powerful he was – and I stood up for myself and for others. And I am very proud of that.
“It was kind of my defining moment really. You will have to watch it on YouTube, it is very good.”