There are disadvantages to teaching gun classes at an outdoor gun range to be sure. Chief among those is the unpredictable nature of the weather.
Nobody wants to deal with wind, mud, rain, snow, or cold when they are learning to shoot or passing a government mandated class or qualification.
However, training outdoors has a number of significant ADVANTAGES as well. Here are a few:
Easier To Hear And Understand
Indoor gun ranges are notorious for being too loud and making it difficult to have conversations one on one. Imagine trying to listen to an instructor who is addressing their comments to 5-10 people in a hard to hear echo filled environment which by nature and law probably has extremely loud HVAC machines running at all times the lights are on.
Now compound that issue with the reality that most indoor gun ranges can't afford to shut down the entire range to accommodate a class taking place on a weeknight or weekend when they make the most money from range fees.
So in addition to the HVAC and the loud echo effect you are now also trying to hear over the sound of other shooters on the lanes next to you.
An outdoor gun range comes with none of these challenges. You will be able to hear me when I talk and I consider that not only critical for your education but also for your safety.
More Time Spent Shooting, Less Time Waiting
Indoor gun ranges are only so big and as mentioned above you almost certainly will be sharing your range space with other shooters. So this tends to lead to a situation where students in the class take turns using 1 or 2 shooting lanes while everyone else waits their turn. It leads to a lot of waiting and not a lot of shooting or learning.
At the outdoor range we can line up all the students in the class on a single firing line without a problem.
Concussion Effect
In addition to being louder, the effect of the indoor gun range is to cause you to feel the escaping gases of the guns physically. Safe or not, it isn't ideal for anyone who is newer to shooting. It has the tendency to exaggerate all the negative aspects of shooting and create sensory overload.