For me, it'd be about guest access. Sure, you could give out your codes, and then change them later, but that's a pain (with the Schlage products at least).
I think the main benefit here is that it works with your existing lock, so it could work on apartments, dorm rooms, office doors, etc. Those key code deadlocks have always existed, but never very popular.
The user codes for these products are 4 digits, and 4 digit codes do not offer much security.
I had a 4 digit Master lock in 7th grade, and an 8th grader spent a little bit of time with the lock, determined the passcode (chosen at random), and then changed the combination.
I wouldn't put one of these locks on my home, or on anything that I wanted to actually "lock"
The keycodes are pretty easy to guess. Regular users will only ever enter the correct codes so if you look carefully at the keypad you can see which digits have been pressed. Most likely there will only be 4 of the 10 possible digits used. I've actually encountered keypads where the order didn't actually matter so you could get in in seconds.
Combine that with the assumption that the average consumer probably used a date of some significance for their 4-digit code and in the US you can guess that 0 or 1 was first, 0, 1, 2 or 3 was the third position, leaving you only to guess the second and fourth position.
There are only 24 possible combinations of a 4 digit code anyway (assuming 4 different digits). I doubt the devices do a lockout on the wrong code, so it wouldn't take that long to hack.
>I've actually encountered keypads where the order didn't actually matter
If the order really doesn't matter, then that counts combinations twice (1234, 1243..). There are 10000 possible 4-digit codes, 5040 permutations, and actually 210 combinations.