The time to learn is in the multi-million dollar full flight simulator under the tutelage of a competent simulator instructor
Of all the 737 simulators I flew, none of them were anyway like the real aircraft. Like for anything else, the sim is a good procedure trainer. And the same for landing, to get a feel for the timing of the event (callouts, when to reduce thrust, when to make flare inputs)..
But there is a risk!
For comparison, I recently I flew with a fresh F/O. His rotation was very brisk (enough to get me startled and holding my thumbs on the control wheel to prevent him from over rotating). By himself, he paused the rotation at 10 degs. Later on, we talked about his rotation and I asked him where he was looking during rotation. His answer was on the PFD, because that was what he had been taught during the type rating in the sim.
That is the problem with the sim for anything that is relies on vision - it's 2D. So to compensate you have to do things a bit different in the sim. Like keeping an eye on the PFD during rotation and flare. These are techniques that are NOT desireable to bring over to the actual aircraft.
So, I agree with your post to a certain extend. The COMPETENT simulator instructor should emphasize the pitfalls of the sim. But since the instructor can't see exactly what the student is doing or where he is looking, it might go unnoticed and the topic not brought up.
As in the case of the guy with the rotation, I am pretty sure that no one intentionally taught him this technique. Probably, rather it was mentioned to him to keep an eye on the RA and pitch during rotation as an aid in the sim. And unnoticed he brought that to the aircraft.