I'm not a salesman but I imagine if you're trying to sell them to a factory owner, you'd play up the problems with the worst humans. Humans come in hungover, still drunk, or not at all. And don't call in. They complain about every. little. thing. "Why do I have to do it this way?" "I don't want to do it like that".
They take long bathroom breaks (and think you don't notice, because they think you're stupid.) They steal. They fight with each other and need managing aka children's therapist for their bullshit. Which never stops. You can stop wasting your time dealing with the "human touch" and get back to what you really want - making more widgets so you can sell more widgets so you can make enough money for that kitchen remodel/winter/summer home/yacht/European vacation/jet.
Fire them and replace them with RobotWorker. It doesn't get drunk and cause fights or HR incidents because it can't keep it in it's pants. They'll work all through the night and through every holiday, without the same trouble of having a second and third shift. You don't need to follow OSHA with these things, though you still don't want to damage them - there's a support contract but that's unnecessary downtime for you, and you don't want that. Still, you can just replace a robot's arm. Just imagine the lawsuits when that happens to a human employee.
blahblahblah. I'm sure you can come up with more.