You are right. We use the term shellac here also, and that is what bin is. I suffer from a disease that affects my brain, so I get terms confused sometimes . I have used Bin in house painting. But it is only suitable on the interior as far as I know. Drying time is not consistent, depending on temp, thickness, circulation, and humidity. Put a coat over the top of it before it cures completely, and you end up with a cracked finish.
I often apply a scale texture to my wood lures. Bin would obscure that, since it goes on pretty thick.
Using a water based acrylic (Createx is what I use) takes about 10 seconds per coat, including drying time (with hair dryer). Yet it goes on so thinly that the scale detail remains so that future coats can utilize the detail to provide contrast. As far as durability goes, Acrylics have been used in exterior paints for at least 50 years. I am not sure about shellac. That being said, I would never fish a bait painted with acrylics without a topcoat. So maybe the point is moot. If the topcoat remains intact, so will the primer and paint. Unfortunately, that is not always the case.
If something is working for you on a consistent basis, by all means keep doing it. I am just throwing my two cents out there so that others can consider the pros and cons. Maybe they are painting plastic or wood baits with fine scale detail. Bin may not be the thing they should use. However if you are painting a wood bait with a smooth finish, perhaps with some wood grain still showing, Bin might be just the thing.