I don't have anything against blue-collar workers. I was one for many years. My parents have been blue-collar workers their entire lives. And it's true that the attacks are often personal in nature. There are a lot of talented witnesses who never fully capitalized on their talents due to terrible advice given by WT leadership.
However, the problem is with the Watchtower sending these men to address issues that should be addressed by professionals. You wouldn't call a psychiatrist to unclog your toilet. Why would you send a plumber to counsel the mentally ill?
There was a teenager at our hall who was clearly suffering from severe mental problems. I remember one of the elders talking about how he had gone to counsel the family because the boy was hearing voices telling him to kill his mother. They prayed with the family and encouraged them to throw away any possessions that might be connected to spiritism. The elder was a welder.
This is a real concern and it can't be addressed without making specific reference to the men being completely unqualified.