So what? Where did he say that his evidence is comprehensive and a world-view of all relevancies to Arts.
When you study a subject, you might want to find some information about one topic. You go to the library and look for that topic.
In a similar manner, if you want to find out about employment outcomes for Arts graduates, you come here to Brendan's thread. If you want to get information about Arts for something else, Brendan probably isn't your expert. Brendan is well-researched in employment outcomes for many fields of studies!
He is providing what may well be helpful evidence [to Arts students as well as Arts-bashers] however has had a few sly digs at Arts, such as when he said "I do not think taxpayers should be funding *esoteric Arts subject*" without at the same time stating his view that taxpayers shouldn't be funding *any* uni subjects. I'm not too fussed at those jibes, but he does dish it out, so it's for him to "put up with" annoyed responses.