If I wrote on my blog that you eat hobbits, my blog is a primary source for "Ken claims Mr. Dalton eats hobbits", but an unreliable self-published source for "Mr. Dalton actually does eat hobbits". The former is an event that happened on my blog. The latter is unreliable info about a living person.
Absolutely true.
Most people who Google someone's name and come across a Wikipedia page about them will be using Wikipedia as a source in the latter, unreliable, way.
I'm sure I understand your point. People using sources badly isn't our problem...