I know I'm coming out of the woodwork here but this needed a reply.
In regards to OP, I understand being frustrated, but forcing people to learn through legislation is not going to prove productive. Instead of being frustrated with customers for not knowing what they're doing, how about offering some help. Instead of "telling them their gun is dirty and getting a look like you slapped them in the face" How about doing something like this:
You: "you know while I was looking at your ________ I noticed the slide was not moving freely and the trigger was a little gritty. If you have a second, I'd love to take you over here to the side and show you how I recommend you clean it regularly. Not only does it keep it functioning, but it also helps it last longer and maintain value."
It sounds cheesy, but it would BLOW MY MIND to see a salesperson do that. Do what you can to change the world around you and lead the way, but please don't force these things on me by asking for tougher laws.
In regards to having a problem with this:
"I've never fired a gun before, I don't know anything about guns, but I want to get a CHL".
I will assure you that I too think they should be properly trained with a gun first. But, the 2A guarantees that right regardless of any proficiency. I think that individual has the responsibility to themselves to train, learn, etc...but not to you or I. They are exercising a constitutionally protected right.
OP is having good insights, but there are better ways to make this happen.
-nick
Opportunity is missed by most people because it is dressed in overalls and looks like work. - Thomas Edison