It's called "hurt yourself on the job helping someone with luggage and you're SOL."

While I have certainly seen my fair share of willing FA's offering to lift a bag, push heavy items into the overheads, or even rearrange an entire bin, many will do as you described simply to avoid being "drawn into" a situation where they are expected to lift.

I can dig that.

In my opinion, if you pack it, you lug it. I know you were probably referring more to the "looking on" rather than the actual lifting, but I'd stand back too if I knew I'd be out of work without pay if helping you brought on an injury.