First, thank you for posting the section. Second, I don't see anything in the section to warrant your comment about the clerks. The requirement is straight-forward. Spend $10,000 or more in cash....you are on the list. Don't spend $10,000 or more in cash....you are not on the list. The clerk, pissed off or not, has no discretion under the law. (Which I assume will irritate you even more.)
The idea that we should deprive all people of the right to purchase items with cash is the same type of thinking that says we should do away with the right to own and carry guns because some people do bad things with guns.