That seems especially cynical to me. I think the whole reason they give out the errata for free is so that it is easily accessible and doesn't require the customers to make any further purchases.
You're missing the point.
While the errata is free, a company with the size and experience of WotC should have fairly minimal errata, or its errata should be in obscure places. What I believe ExploderWizard is saying is that issuing errata is fine - with a system as complex as just about any RPG is, it's actually to be expected. But the VOLUME of the errata being released is the issue.
Some = okay
Lots = bad, even if it's free.
Lots of errrata points to having done minimal editing / internal review / proofing / lack of quality controls. A company with the resources of WotC is expected to do that stuff better than most.