SEO is a relatively new field, so we are all pioneers in a way, however there is a lot of self help information out there these days (ala Gooruze) and also formal training so I think his comment that you quoted above is relevant to about 8-10 yrs ago, not so much these days...

Clay, yes, but that's exactly what he's criticising.

In part of his post he points out that much of  the self help information is merely the collective opinions and beliefs of the seo community continually being repeated by anyone and everyone, and not based on any formal, or scientific basis.

He points out that many search engine "experts" jealously guard their key secrets to maintain their competitive position.

He also argues that the search engines themselves are not going to fully divulge how their search algorithms etc work for fear of it being abused.

And in that environment, it is all but impossible to get any universal scientific basis for a formal education in the area.

It is a valid argument. And it's worth reading the full post to understand where he's coming from.