All he is saying, and this is a good point, is that the long time use of something isn't indicative of it being good for you. Going to church has been around for 2000 years too, that doesn't mean that it's healthy, it's just something people do.

>Thousands of years of compounded experience?

This makes it seem like you ascribe some qualities to old ideas, because they are old. E.g. it's old, so it must have been tried many times and determined to be better than other ideas.