Simple elegant solution. Sack any journalist who uses Wikipedia as a primary reference source without checking the facts as they are obviously not a proper journalist and so should not be reporting on anything at all.

When word gets around that it costs you your job to use it, journalists will stop using it, an studying relearning the age old art of proper Journalism.

This may not fix wikipedia but it might at least bring some respectability back into the media, which i think most of us would agree is now sorely lacking...