The BBC radio presenter gave his view of their rendition of John Lennon's classic Happy Christmas (War is Over) during his show.
The outspoken DJ said he did not agree with the Pop Idol finalists' single because he thinks that when John Lennon and his wife Yoko Ono wrote the song it was about their personal feelings on war.
He also called the Pop Idol stars 'mediocre'.
Kirsty, pictured right, said: "He made a few comments about Pop Idol and I see exactly where he's coming from.
"From the outside I can see how the single release can be seen as a money- making scheme.
"But the idea of the show is great and it gives people like me the chance to show their potential.
"I felt like writing in about him
calling the finalists mediocre because it's not true.
"You can't knock their talent – the final 12 were narrowed down out of 20,000 people."
Chris Moyles asked Radio 1 listeners to text the show to see if they wanted him to play the. The majority voted for him not to play it.