>putting retail workers in the position of having to even ask people to leave is too uncomfortable and potentially even risky.

That's why some employees get paid a couple bucks an hour more to be a shift manager. You also don't need to directly confront people after 1 hour, you can be passive-aggressive with any customer bold enough to stick around for 4-5 hours. The policy isn't meant to be taken literally, it's more of a deterrent and a pretence for action.

Dealing with customers not leaving is just part of the work in retail. Somebody needs to be the person who draws the line and tell somebody to stop loitering and leave. Some people will literally live in the coffee shop if nobody stops them, never mind staying there for 8 hours not buying anything.