You are getting into an area that I feel strongly about. . As I have stated often before. The majority of golfers learn the rules from other golfers. Many carry a rule book ( because they are free ) but have never read it . And then expect to immediatly find a solution when a situation arrises on the course. They then complain that the rules are difficult because they have never read the book or even learned how to use it. Many would not look at the definitions section at all and that is probably the most important section to understand.
You are quite right, pom, they don't know the book. They're in a situation, pull out the book, go to the index thinking of a relevant word and it's not there. Think of a synonym and it's not there. Third try, fail, put the book away and claim the rules are too difficult, they're holding up play. Ask someone, get an answer (any answer will do) and play on.
Would they look in the definitions? Hell, no. They know what are bunkers, water hazards, obstructions and the boundary fence.
There's far too much tedium in the rules. So much that, for the great majority of players, it's 'over the top' and they couldn't be bothered. Not many have a 'legal' mind and don't want one. Let's not get started on the Decisions book.
The rules and decisions attempt to cover all possible situations and do a quite good job of that almost impossible task. Most players are not that 'into it' and don't want to be. Very few wish to become experts.