Allen, a 23-year-old who currently resides in Conway, AR was crowned Idol's eighth-season winner during Wednesday night's live finale broadcast on Fox. He defeated Adam Lambert, a 26-year-old Los Angeles resident whom Cowell and the rest of Idol's judges had repeatedly openly touted as the competition's winner-in-waiting.
"[Kris] is probably the right winner in terms of being a nice guy," Cowell told Ryan Seacrest during the Thursday morning interview on the Idol host's syndicated radio show. "[But] was he the best singer in the competition? No."
"You know what my feeling on the show is," Cowell added. "I mean he's popular. If you allow America to vote, you live with the vote. I wouldn't have said he was the best singer in the competition, no. He was like a little puppy dog."
Seacrest then asked Cowell to rank Allen in comparison to American Idol's seven previous winners, causing Cowell to just laugh and pose the same question back to Seacrest.
"I'd probably put him in the middle," Seacrest told Cowell.
"In the middle?" Cowell laughed. "Okay, who's below him?"
"Ruben," Seacrest said, referring to second-season Idol champion Ruben Studdard.
"He's below him?" Cowell asked.
"Yes," said Seacrest.
"Okay, [who else]?" Cowell replied.
"Who's won the show, I can't remember!" Seacrest said.
"Taylor Hicks," Cowell offered, referring the fifth-season Idol champion he has repeatedly panned as the show's worst winner.
Last week, Cowell had stated that Allen was "not a good enough singer to compete with Adam" in the finale. According to Cowell, Danny Gokey -- the third finalist who was still in the competition with Allen and Lambert at the time -- was "the only one who can compete with Adam on vocals."
However Gokey ended up being eliminated after last week's performance round, leaving Allen to face off against Lambert during this week's finale.
"Listen, congratulations Kris. Anyone that gets the public vote, good luck to them," Cowell said later in his interview with Seacrest.