Why are mail.app rules so inflexible?

Why just 'all' or 'any'?
Say I want a smart mailbox to display mail that is unread OR flagged, AND only comes from the inbox? It's not tough, but Mail.app can't even do it.

It's actually impossible to set a smart mailbox up with these parameters so you don't get duplicate messages in it. So I'm getting messages from Gmail - inbox and my normal inbox in this mailbox.

I get they want to make it an easy interface for new comers but the limitations are kind of ridiculous?

Hmm nice solution. I r dumb.
Wish there was a way to do it without mailbox clutter though