That flies in the face of my direct experience working with these people, but sure let's take your assumption at face value. By this logic everyone on salary i

That flies in the face of my direct experience working with these people, but sure let's take your assumption at face value. By this logic everyone on salary in any career must be a cheap, dumb slacker, after all there is no difference between accounting on salary, plumbing on salary, writing software on salary or working in a warehouse on salary. The exact same logic applies. Or maybe, just maybe doing plumbing on salary has the exact same set of tradeoffs as doing any other job on salary and people choose either for different reasons.