[jsmith45]

Actually, I suspect it is very deliberate.

For normal master lock key padlocks, it is not a big deal if it accidentally unlocks with somebody else's key.

Their normal cores are shitty enough that even a regular key has a reasonable chance of acting like a bump key, so if you insert the wrong key quickly and turn, it might just open.

With LOTO locks, Bob could die if Alice's key works on Bob's lock. (e.g. both on working on equipment powered by different circuit breaks, and Alice confuses the breakers, and removes the lock from BOB's breaker, because her key happened to work on it).

A few reports of that happening, and their LOTO locks could be banned from many worksites due to unions insisting on it.

Now to be clear, the master LOTO locks offer basically zero physical security, since they can be very easily destroyed or bypassed. But to my knowledge, no master branded lock offers any real security, so that is hardly surprising.