I thought he said it was a $7 upfront charge per person and that it isn't mentioned in the tipping guidelines. I don't know if that is correct and $7 isn't much, but who here does not scour their final bill for any unforeseen charges? I know I do.
If I saw an odd $21 on my bill I wasn't expecting for a service charge I didn't think I received the service for I would mention it to the front desk. I am guessing that is what Joe did, and he was told it was for deckhands and bellmen. That's a new one on me and it is a valid point to mention it here.
You're OK Joe. Don't worry about the snide comments. Some things like $7 seem small, but it is how they are done that counts. It all adds into your cruise experience.