CNN

(CNN) – After days of being criticized for an off-color joke about the daughter of Alaska's Republican Gov. Sarah Palin, late night TV talk show David Letterman got a vote of support from a fellow comedian.

Bill Maher, host of HBO's "Real Time," called the apology that Letterman issued Monday "a real shame."

Related: Letterman apologizes to Palins over 'coarse joke'

"David Letterman should not have had to apologize," Maher told CNN's Wolf Blitzer on The Situation Room. "I've known David Letterman a long time."

"He's a very fundamentally decent Midwesterner. It's just not in his DNA to have said something that they're accusing him of saying," Maher added.

"It was an easy and obvious joke to make. It was funny. It was not offensive in any way," the HBO host said after detailing his take on the circumstances leading up to Letterman's controversial joke. "And they made it sound like he said something completely different. So he's apologizing for something he never meant, never thought, and never said."

Related: Palin accepts Letterman's apology

"I've been through this," Maher told Blitzer. "It stinks."

Maher's show appears on HBO, a sister network of CNN that also is owned by Time Warner.