Agree with Ojgalli statement of "Downsides delicate, easily overdriven, higher distortion, beaming dispersion pattern."
These are well known and accepted drawbacks to ribbons and it answers the OP's question of why they aren't used as widely as other types of tweeter.
These are well known and accepted drawbacks to ribbons and it answers the OP's question of why they aren't used as widely as other types of tweeter.