As far as I know, "wiki" is not a synonym of a website with contents that everyone can edit. There are lots of wikis with locked-down pages that only the admin can edit, wikis that can only be edited by certain people (e.g. people who register and send an email somewhere asking for write permission), and even wikis (like the Bitcoin.it one) where one must pay to edit.

Personally I think that requiring a Bitcoin payment to enable editing is a smart feature to prevent bots from posting spam, and it ensures that the editor knows enough about the subject of the wiki (Bitcoin) to create bitcoin transations. About the fee being too high... well, some months ago 0.01 was "nothing". Now the standard for "nothing" is more like 0.0005, or even lower. That the fees are high is a more adequate subject for discussion, in my opinion.

EDIT: seeing that, as described on https://en.bitcoin.it/wiki/BitcoinPayment , the proceedings from the payments are used to keep with wiki online, and since probably not that many people are signing up, maybe the fee is not that high.