Regularly pulling a hash for the libraries you include and alerting you when a hash changes unexpectedly is no work at all.
And if you need to be paid money to fix it then you have a problem anyway so one would assume that you'd be paid just as much to fix it when you're being alerted to it by a cron job as you would be paid to when you're alerted by a horde of users.
As for machines without guards: I've worked (extensively) in the metal working industry and the number of people missing digits and limbs has decreased steadily ever since tampering with guards, safety-interlocks and lock-outs became a firing offense so I don't think that's a very good example.
Machines: Yes this was the 80's (sorry I didn't point that out my mistake) and things have changed. However to that point if you have your golden machine operator turning out good work (and he is only 1 of 2 on a particular line) and it's not easy to hire a replacement, let alone a good replacement, you tend to get a bit lax.
Security: I am primarily a business guy (who does some light programming and knows Unix since the 80's) so I hire others to do work for me. I am just thinking that for the people that I have hired in the past how would anyone know if any of this is happening (other than code audits) and what is the mechanism to make sure the right thing happens even if you know what the right thing is? It's kind of a version of the advice "make backups but make sure that you test your backups as well".
The motto is 'trust but verify', and indeed that goes for your backups as well. And incidentally that's one of the most failed items during the dd's I've done and after verification several companies turned out to have lived without backups at all.
It usually takes two things to go wrong for a disaster to happen: some $0.05 part that fails and a procedural error.
One of the first books that I read talked about the story of the backup tapes on the car seat that were erased when someone in Sweden (?) with heated seats drove home. (urban legend iirc).
Iirc Saab pioneered heated seats because one of their engineers had colon cancer and Saabs are pretty common in Sweden, but I'd still wager that's an urban legend because the heating is done with DC current and to reliably alter the contents of a tape you'd need a lot more of magnetic field to overcome the resistance of the magnetic particles to change direction (remanence) and you'd want that field to alternate.
And if you need to be paid money to fix it then you have a problem anyway so one would assume that you'd be paid just as much to fix it when you're being alerted to it by a cron job as you would be paid to when you're alerted by a horde of users.
As for machines without guards: I've worked (extensively) in the metal working industry and the number of people missing digits and limbs has decreased steadily ever since tampering with guards, safety-interlocks and lock-outs became a firing offense so I don't think that's a very good example.