Fewer people really carry with little to no training
I have talked to a lot of people who took short classes and about half decided not to get their license or if they did, not carry a firearm, as they 1. had no clue what or how to do it, or 2 the instructor told them the liability didn't make carrying worthwhile. Then those that took the longer classes felt more at ease in carrying, and around 90% did carry. It is a human trait not to do things they do not know how to do.
Among law abiding folks, I see 4 types Gun owners, People who own guns, people who don't own guns, and anti-gun people. Now for the vast majority of Gun owners they are pretty knowledgeable and some fairly skilled, then of the people who own guns, some have knowledge, and a few have some skill, a lot are like Barney Fife when it comes to anything beyond shooting paper. Then when the people who don't own guns start signing up, Instructors can take the time to educate them, or just process them through.
Do not assume they all know what you may know, and trainers should remember that their students may only have what they learned in class to defend themselves