So why doesn't the average beginner do these three things? Answer: it's boring.
It's boring to fold.
It's frustrating to fold halfway through a hand.
It's dull to never bluff.
In other words, good poker--especially at the lower limits--feels to a beginner like boring poker. Now, this of course is incorrect; once you master the Zen of folding, you'll realize that good poker is anything but boring. It's stimulating and challenging and full of surprises... ah, but to a beginner, who hasn't gotten very far on the path to poker enlightenment, "good" poker seems incredibly boring.
This is a fundamental reason why teaching a beginner to play good, solid poker is so damn difficult. It's easy to tell a new player to fold ATo UTG, but it's another to get them to actually do it on their own. It's unexciting for them to sit out 80%+ of their hands. They came to play, dammit, and that ATo looks so shiny and bright.
It's similarly easy to tell a new player to fold to a river check-raise, but good luck getting them actually lay down their made hand. And you can preach the gospel of Value all day long to a new player, but they see big bluffs on TV all the time, and they want to partake in the fun.
It's like the concept of death; we all know we're going to die, but few of us actually believe it. Similarly, a beginner can intellectually understand they shouldn't play A-T offsuit from EP, but more often than not they don't really believe it. For these players, the only way to truly learn this lesson is, sadly, by negative feedback; they actually need to get punished enough times for making the wrong play that they begin to see the light. That's when the "a-ha!" moments begin to arrive in force. Good, winning poker may look boring to a new player, but then so does walking to the cashier's cage with a rack full of chips. It's all relative.
All-in for now...