I play 40k because it is:
realistic enough (most rules follow something vaguely logical at least)
interesting enough (I love the fluff)
convenient enough (find a game, learn the rules)
cheap enough (to buy, commission, play all the armies I want, etc.)
…for my imagination (I am also an avid reader, but there is something special about enlisting models to do the killing)
In conclusion:
At the end of the day, I just want to laugh with friends and play a game that lets me create my own action movie.
40k fits the bill for me for now. When GW moves in a direction that isnt compatible with my personality, I’ll move on to the next hobby.