Raising the cost per plane is not so simple of a solution in some markets, and may make it very difficult to stay competitive, putting you out of business there entirely. Also, not all planes might be purchased for passenger travel, maybe a plane is used for package delivery and doesn’t need to come with so much extra safety. Who knows.

In a world where air travel is remarkably safe, throwing in the extra fire extinguisher that may make the difference between a near miss and a tragedy seems like it'd pay for itself many times over versus the alternative even if you just consider the PR impact.

My thoughts, too. Certain core safety features should be included by default, to avoid the possibility of an uninformed buyer dooming the people flying their airline.

Auto manufacturers don't make an engine compartment firewall optional, or sell full-strength seatbelts as an upgrade.