I would compare it with target shooting with a bow (simulator) vs. bowhunting for deer (real world).  You learn the basics and it is good practice, but very possible to learn bad habits and practices that are hard to break and it doesn't teach you how to react to the weather, wind, unforseen problems and other "natural" phenomenon.

Running models are a different animal from simulated models.  You seldon see a simulator with rough dirt or overly long grass that trips the model while it taxis.  And the engine is already running when the model appears.