"Is anyone at WOTC paying attention to what they print any more?"
Yes, because they got 99.9+% of things right.
But you find one erratum and make a post with a hyperbolic title like this.
OK so if you are going to start throwing numbers around 99.9% right means they got 1 in 1000 monsters wrong.
The monster manual has 500 monsters (give or take) so if the Carrion Crawler is the ONLY monster they got wrong, and they got every other monster completely right, they still did not meet the 99.9% threshold that you posted.
WOTC did not get 99.9% of monsters right, that is just fact (unless you think this one is right).