Pick one example where the content has a flaw and use it to claim that all of his content is therefore "useless". I don't know the author's motives. You don't

Pick one example where the content has a flaw and use it to claim that all of his content is therefore "useless". I don't know the author's motives. You don't know the author's main point either. He did not assert this at any point--he instead commented on the necessity of expert/experienced input in developing these videos, using the decimals content as an example.