Personally, I’m fine with a working lunch, as long as I stay clocked in. Because it means I either pick up OT at the end of the day, or I get to leave early. But this only works because I have a fairly flexible schedule, set my own meetings, etc… And I certainly wouldn’t try to enforce it on my coworkers, because they may want to be able to walk away and disconnect for a while.
Meal time is time for whatever you want to do; If you want to stay at your desk and play catch-up on some emails, then great. If you want to walk away and de-stress for an hour, then great. Neither one should be the expectation, because the time should be at the employee’s discretion, not the employer’s.