It certainly depends on who you ask. Maybe people can't shake the fact that Jane Fonda and Ted Turner started the station, and they're well known as being liberal. There is also the bit where CNN was hiding information Hussiens brutality so they could keep their offices in Baghdad, even enableing Saddam's sons to kill two family members that were intending on providing information to the West.

Personally, I always like Headline News except that you only get 1 min on each story.