The other day in a class about writing more efficient email, we were talking about Ccs (courtesy copies) and the use of Reply to All. One attendee bemoaned the fact that people purposely dropped her boss off the Cc list. She wanted her boss there to keep him informed. So why did people not Reply to All and keep him in the loop? Were they trying to get away with something?
Nope. They were trying to help everyone be more efficient by reducing the use of Reply to All. Or they were just replying to her because she wrote to them–he didn't.
Not Replying to All can be a conscious good choice, or it can be an unconscious automatic choice. It doesn't have to be a sneaky or calculated one.
Here's the solution if you want your boss to read the replies you receive: forward them to him or her. If it is important that your boss read them, it is probably worth that small effort.