The pursuit of realism must never conflict with the pursuit of enjoyability.
I am a big proponent of realism in videogames. What I realized at some point was that the primary purpose of a videogame is entertainment, and thus anything that detracts from enjoyability has no place in a game. Simply put, realism per se is neither good nor bad; it simply is. Realism should be pursued when it contributes to both the design goals and enjoyability of a particular game.
Using 'fast travel', or more accurately, teleportation, as an example: Being unable to instantly transport oneself to a desired location without a valid in-game justification such as magic is more realistic than being able to do so. The decision by a dev to disallow it--at least until 'earned' in-game in some manner--would be legitimate, because it trivializes a game's overall progression, and by its nature eliminates portions of gameplay.
On the other hand, leaving out the necessity of paying bills every month, while certainly less realistic than having to worry about them, is legitimate, as it does not detract from enjoyment (for 99% of people, anyway), whereas including it serves no conceivable purpose other than realism (again, for 99% of people, presumably).
To go further, even if some gameplay element was created in which the timely paying of bills was important, in reality, it is possible to automate such payments. The act of paying bills is not in any way, shape, or form entertaining to any person that I am aware of, and therefore there is not really a good argument for forcing one to do so in a game.
Things like firing weapons, engaging in combat (paintball e.g.), problem-solving, treasure hunting, walking, running, hiking, making money...busting bricks, eating mushrooms, and exploring sewers...etc. are fun in reality for many people, and thus it makes sense for these activities to exist as elements of a videogame.