yes there should be a minimum karma to edit wikis and new users should never be allowed to edit wikis.
... you can't stop people from adding to wiki's, loads of unregistered users have provided useful info over many years. Also the wiki page has a simple math problem to avoid autobots.
most of the new members come here and start a new thread just to ask some questions about their device or to solve some problem they are facing.
about spamming our mods are doing great job.