We used to drive around in cars without seatbelts and airbags,
I (and others) still can, quite legally, in the UK. The Government did not require retro-fit of seatbelts, fog-lights and other "safety" items. And that is also a matter of principle.
This proposal does require retro-fitting of equipment which, as has been pointed out, is not feasible for smaller aircraft, whether or not a commercial flying school has to pay for the fit.
So does that mean it will never happen, or can never happen?
If we legislated for every possible accident, would we ever be allowed to get out of our beds?
Cheers
Whirls