I don't really think that the two are antinomic. There can be good and realistic gameplay.
But I generally think that reality is a very good inspiration in order to set good gameplay mechanics.
Indeed, you start to think out "it would be cool if i could do that", and you start to elaborate an idea on how to integrate this in a Civ game, taking account in the move of Civ initial mechanics.
As to realism by itself, it can be good when it gives you a great experience.
My experience was with Civ2, when i started, after a while of playing, to say to myself: "it is just like i'm ruling an empire among other empires". It was to the point where the player's civ starts to be surrounded. That experience was directly linked to reality. That was not "i play a dumb video game" but: "i rule a country". In Civ3&4, culture borders didn't allowed myself to say that to myself, because it was written on the map since the start of the game (cultural borders) That's why I prefer when the simplistic mechanics of the game make a link to reality through the player.
So yes, realism is important, but the more important is to let the player to probe it.
After all, Civilization was not designed to add a strategic or brain game to the video games, but indeed to let the player to rule an empire since the start of the civilization, within the simpliest (and most fun) way possible.
So that it is the experience that counts the most. No need to play on Deity, Settler will make it, or Noble if you want no difference except your brain against AIs and your civ. You think you are winning to easilly and outpassed the AI by a too great advantage, making the experience less tasty and confined only to what you did in a particular game? (example: war) Move up some difficulty levels, and you might feel another taste of Civ.
And about the experience, it is to say to live with a civilization from its start, what can civilization V bring more than we already experienced? Hard to tell. And I defy anyone to tell it. But sure, some of the new ways to manage food, science and production that are exposed in this forum are interesting.