Why are they not allowing us to edit parents guides anymore?

Hi Matt,
We are in the processes of releasing our new Parents Guide page.  We will be re-enabling contribution for existing Parents Guide contributors shortly.  Additionally, over the next few weeks we'll be expanding contribution to all registered users, removing the past need to request wiki edit access.

https://getsatisfaction.com/imdb/topics/new-parents-guide

Thanks
Nic