Ok, we can all agree that until a high level of automation is achieved, such jobs are necessary.

But how many of the people defending the need for such jobs would actually want to do them?

Usually they're happy to let other people do them, but would balk at doing them themselves.

This is especially true for "dirty" or "unsavory" jobs such as garbageperson, exterminator, food processing / slaughterhouse worker, etc.

People are usually happy to hire such people or consume their products, and talk about how essential they are, but would never want to be one themselves.

On top of that, they'd usually look down on people with these jobs and never dream of associating with them or inviting them to their parties.

QED

After all, who'd want to shop groceries at a dirty place when there's a nice, clean place just a bit down the road?

And of course, all of this is even more important for the reason the article highlights: These are the jobs people end up in now. In a country with a vanishing middle class and terrible social safety nets for seniors, increasingly large numbers of people end up here. Not just criminals, those who aren't especially bright or those who are a bit unlucky, but good, capable ordinary people have nowhere else to go now. If we're all going to be living here now, we need to start cleaning the place up.