It's not a straw man argument because the statement was made by the person and the Buddhist organization he was promoting. One can't straw man oneself. It is also an idea found in the original and earliest Buddhists texts.

I agree with you and I state in the article that some of our thoughts are more valuable than others, but importantly, we decide how valuable they are. What Buddhism, in general, teaches is that we should see our thoughts as illusions and by so declaring them without value, we can reach the state of No Self. More recent Western Buddhisms have modified and watered down that central tenet.