They are specifically talking about "general intelligence" here, something which hasn't been achieved and so we can probably classify all attempts towards it as failures at this point.

I don't think that the author meant to write off the entire field of symbolic reasoning because Cyc didn't achieve general intelligence but I think it's fair to say that the lack of progress Cyc made towards it does make it less likely that purely symbolic reasoning will lead us to AGI. That's not to say it might not play a part in AGI or that it doesn't have other uses.