Sure if people could just pick whatever they want we'd all be sitting on the beach having drinks with supermodels, but then who's going to make the drinks?

People can pick among various jobs. If they picked warehouse worker that was the best option available to them. Taking it away means they have to choose something worse.

And a job is not a lifetime commitment. Warehouse worker may be a stop on the way to something else. I worked in a warehouse for a while, now I don't. People are not static blobs.