Leaving aside the wikiquette and formailities, the mediawiki software itself makes it tough for newcomers. Even one Post-Doc friend of mine could not figure out the simplest wiki syntax! People are more comfortable with WYSWYG editors. I had been watching wikipedia for last 3 years. MediaWiki has hardly shown any improvement in usability and interface. It's time more developers put in more effort in improving ease of using media wiki. Other free software around the same time frame have improved dramatically.

Thanks

Ravi