unions

That's not entirely true, the idea of specialized jobs being paid more is due to the fact the worker had to invest time or money into the skill. The point being made is that a low skilled job generally shouldn't be paid more than a skilled job, due to education/training costs.

That's the arguement being made, and drawing attention to the fact that Boeing could lose generations of techs to other careers (forever) if they don't act now. Because once someone moves away from the field, it's hard (time and money) to bring them back.