To warn future researchers they will be wasting their time if they join. I know some folks don't care about reputations, but this guy already established a rep

To warn future researchers they will be wasting their time if they join. I know some folks don't care about reputations, but this guy already established a reputation as a leader and should not have to do what he did to justify working on a project (PhD in his field from MIT, worked at AT&T as an MTS, which was a coveted role, for almost 2 decades, professor at a Tier 1 university. To me, if somebody with that level of background at high-value institutions is willing to write this, it means it's true, and important, and should be paid attention to by the appropriate constituency.