Its not black and white some of these jobs might be shitty but atleast someone gets a paycheque, the other alternative is that these people depend on unemployment benefits and then vote for demagogues who promise to bring back jobs and drive out immigrants who stole those jobs.
I can't see how it would be better than if huge swaths of people didn't do anything and lived in squalor. Who cares how much it affects the GDP. Honestly I'd probably find it more rewarding to operate a train for some people than all of the professional programming work I've done.
What’s wasteful about paying millions of people to shovel dirt?
Now take your answer and apply it to your question.