They did not believe that the Panda existed. Some still don’t. They are the more die-hard of the skeptics. They think that believing in Pandas is akin to not having yet grown up and learnt to wipe ones nose. They think that Stephen Hawking has the low-down on what the universe is like. They imagine that Suskind was right to leave plumbing. They imagine that Phil Plait can see things when he looks through a telescope, other than exactly what Phil Plait wants to see.
These are the Panda-deniers. They want to move our thinking forward to a new and greater enlightenment. They point out correctly that science has established, by peer review, that bears never had, never could, and never will, live off bamboo shoots. They wonder how anything that looks like a teddy bear can get down to serious reproduction. They assume that the panda, as advertised, would be already extinct.
But what do they know? Its not as if they are ever going to work out that Pandas are indeed real. And that they are really a bunch of Chinamen from the communist tourist department wearing a suit. The Panda denialists lack the necessary guile, to see the world around them as it is, rather than how they would wish that world to be.