I don't leave my lock at work since I'd be carrying a lock with me anyways. Sometimes I take an unplanned detour somewhere on the way home.

But at work there's easily a couple dozen locks which at least half haven't been used in a few years.

One place I worked at actively discouraged the practise. They'd cut all the locks off a couple times a year.

True, but isn't it safe to presume that the lock is going to be there by itself longer then it's going to be there used to secure the bike? Plus (sadly) given all the YouTube videos of people stealing bikes and bystanders not doing squat about it, who's really going to give someone messing with an "abandoned" lock anymore attention?

And I too agree with Slim in that the best defense is not to be too predictable.

For me that isn't a problem, as both my U-bolt and cable locks remain in my pannier bag. Unless of course my bike is locked up. Keeping them in my pannier bag(s) there's no worry about "forgetting" them.

And they're just a "small" drop in the bucket of the weight that I regularly carry on my regular commute(s). and as I've said in other threads even with all of the weight that I carry I am still able to maintain a decent speed.