Well. Given the smaller user base the *BDSs are good candidates for a very low footprint secure OS installation. In our org we use an openbsd instance to run our low traffic but extremely secure master database. The system really spartan and has a very low footprint. It is sufficiently different from Linux that the casual automated attack wont work. Things like NetBSD are a useful starting point to getting an OS up and running on a new architecture. This happens quite frequently in research settings.