No because it is still what you paid for. They have a right to work in an environment where they feel safe. If they’ve requested a plexiglass divider, there is a reason for it: this could be to help protect a sick family member, contractual obligations (remember if an actor gets sick during filming, the entire set loses a job until they are better) or a multitude of other reasons. If you don’t want a picture with the plexiglass, that’s fine - forfeit the ticket. The service is being provided, you’re choosing not to avail of it.