The quality of technical articles on Wikipedia are second to none. Time and time again technical references have played out in personal and professional endeavours. They're clear and concise.
You've got to accept that some topics, biographies for example, are inherently subjective and can't be purely objective.
Wikipedia is the most rigorous source of 'truth' available to the masses, and the complaints of bias are about bias which may indeed be present, but are markedly subtle. Where is the source of 'truth' that's anywhere near as objective as the offerings of wikipedia?