I dunno, if you've visited Longleat recentley you'll see they really do go high on their education; panels on sustainability and man's destruction of the Earth's resources are all over Animal Adventure, the talks both there and on the safari boat commentary carry strong educational messages, the safari park has both a guide book and free audio CD to make up for the inability to have signage in a drive-through reserve and the Park DOES work with conservational organisations such as the TUSK trust and the Diane Fossey Foundation (the latter of which visitors are encouraged to donate into the box after getting off the boats). And they're scope is certainly going beyond the usual safari park scope, with bongo, warthogs, nyala, siberian weasels and giant anteaters joining in recent years: And with the hopeful inclusion of more small exotics in the mini safari, and if animals such as cheetahs and elephants are indeed returning, then I think I can say things are looking up.
Just didn't think it deserved all it's stick.
EDIT: @Pertinax, then let Longleat have some. ;D