I’m not a big fan of front seat pax, unless it’s someone I know. But if they insist on it, I’ll allow it. I understand the annoyance, because I too don’t like having to move my personal things from the front seat.
One trick I learned though, on occasion if you you’re going to get someone you can’t stand, put as much stuff on the front seat as you can, and that will discourage them from wanting to sit there.