Hey there, Lefty!  Thanks for the smile: "...most [gig employees] are below average in performance and errors quickly build up in production."  Yeah, and that goes for millions of full-time corporate drones, too.  Some of them can't be blamed, though.  They've been ground down by the dolts who "manage" or supervise them.

Thanks for the laugh: "If these workers were good, they would already have full-time jobs."  I take it you mean "corporate cubical" or "factory floor" jobs, right?  Hilarious. If you manage to make it financially in what people sneeringly call "freelance", you're likely faster, more savvy, more astute than the average Joe/Josephine in those "full-time jobs."  You have to be--simply to survive. 

And know this: many gig folks will tell you that, in the end, they're only as good as the clients/employers allow them to be, sometimes unintentionally...and sometimes intentionally.