@Euphroe, I don't believe anyone here is disagreeing with you about the
safety of a Restrictor lock in terms of operation. The debate is about what happens when students learn to rely on the Restrictor for that degree of
safety, begin work in another theater, and fail to realize that non-Restrictor locks do not afford them that degree of
safety.
If every rope lock in use today was a Restrictor or even most were, it wouldn't be so much an issue, but the Restrictor is currently a rare breed and unless price comes down drastically, likely to remain a rare breed. It's a promotion of what would be unsafe work methods under other, much more common circumstances. In schools, in particular, it's more troubling yet because students have such a narrow view of the world -- they'd be surprised to learn that not every other theater has the same types of rope locks as their theater does.
Another factor to take into consideration is that, though I'd expect runaways or close calls are not all that uncommon, we hear only about a few accidents a year where someone is substantially injured. While there are safer alternatives, such as motorized rigging with slackline detection and load monitoring,
conventional counterweight rigging remains fairly safe. To that end, I'd not be surprised to learn more accidents happen in theaters annually from unsafe use of prop weapons or falls from ladders.
Taking into account the frequency of injuries in our industry, and comparing the risks versus rewards of Restrictor-type locks, I'm just not sure the risks outweigh the rewards. While that specific theater may have a reduced number of accidents and close calls, the prevalence of accidents and close calls may increase in the many theaters without Restrictor-type locks, who have people working there who have grown up with Restrictor-type locks.
Another thing to examine is I see more and more venues with motorized battens for electrics, and
counterweight for general-purpose sets. Almost always, the most hanging from these
counterweight sets are legs, borders, and drops. Maybe a
mirror ball or a banner from time to time. I actually don't see many schools hanging scenery on their battens in excess of a couple hundred pounds. Certainly none that are going up several hundred pounds on a given
batten, and anyone doing that
level of production probably has a scene shop attached to the theater and proper supervision.
All things considered, I think that Restrictor-type locks in academic environments promote an unsafe work method in the broader industry that students are being prepared for, and that for that risk, not enough reward is to be had. For venues with motorized electrics for lighting (where the vast majority of reweighting would otherwise occur), the number of times a
counterweight set is even used for actual scenery that may weight more than 250lbs is almost none, making Restrictor-type locks vastly overkill for the application.