There is a tendency to over-regulate by prescribing hardware. This is actually a "political" issue, driven by human nature, rather than a technical one.
Those locked doors have now killed more people than they have saved.
In the "parallel universe" of merchant shipping we had the same problem with "release on load lifeboat hooks" - which killed more people than they saved - and we have just seen the regulations changed again.
Time for another cool, calm, look at those doors.