The underlying thought was just that it appears to me that tailstrikes
that are not felt in the cockpit or at least the cabin are much rarer occurances than other safety problems for which warning systems have been integrated in aircraft - at least tailstrikes that were undetected, but endangered the safety of the flight or even caused crashes. I don't know if that's true, I just had the impression and wanted to introduce that angle into the discussion. And I surely don't want to be on the flight that makes a precedence.
I've surely heard of a lot more safety landings because of the failure of gear proximity switches or other devices that created an "gear unsafe" warning of sorts than of real landings with landing gears that failed in some way. (Thanks to the media that make a live TV event out of every airliner circeling to burn of fuel for an emergency landing.
) So I feel that even these important sensors fail a lot. On the other hand, I don't know how often (cargo) door sensors have prevented accidents, as the problems they are inteded to detect surely happen most of the time on the ground, and in flight failures only seldomly make the news...and cargo doors that open for real in flight are even more rare.
I know it's cynical, but this question surely turns up when designing a tailstrike warning system for an airliner. I would sure feel better if such a system was an option on the airliner I'm flying on as a passenger, though.
Just out of humble curiosity...when was the last time an airliner had an accident that could have been prevented by an indication in the cockpit?