Tell me if this makes sense

When composing an e-mail, the receiver's address can be placed in one of the following categories: To, CC or BCC.

Here is what I believe the function of CC should be:

If you receive an e-mail and you find that your address is in the CC category, it means that you are not directly involved with the subject of the e-mail. However, you do have some stock in the aforementioned subject.

A gentleman at the community station I'm helping out at, was insulted because he received an e-mail and his address, was in the To category and not CC. He told the sender that his address should be in the CC category as a form of respect. In other words, the gentleman feels that because he has done his share at the station, he feels that he should be CC'd for all e-mails as a way of respecting and appreciating his contribution.

So with this in mind, what is the real function of CC?

Is it what I feel it should be or, does it match the gentleman's description?

The Hek