Your assumption that a chamber run is safer than a dive is correct, therfore to go to depth in a dry environment where you are not chilled by water and where medical assistance is one lock away is a good reason to use a chamber as a training tool. In commercial diving they are used to do decompression because the diver is out of the water in a warmer and controlled environment. Most commercial dive companies (and the military) have more money to fund the use of a chamber though.
Dull and boring - yes if there is no point to the run. Limited availability - yes if it is the only chamber nearby and you pick the busiest time of the week. A chamber can be depressurized at a safe rate fast enough to allow use to do a treatment, so not doing educational runs because of needing to be on standby for emergencies is a load of c**p. The chamber owner is probably more concerned about liability than availability.
Dull and boring - yes if there is no point to the run. Limited availability - yes if it is the only chamber nearby and you pick the busiest time of the week. A chamber can be depressurized at a safe rate fast enough to allow use to do a treatment, so not doing educational runs because of needing to be on standby for emergencies is a load of c**p. The chamber owner is probably more concerned about liability than availability.