The turn limit is a major pain, but it is necessary.
Because in Civilization, you get points for your population and city cultured. If the sky's the limit for turns, you can just stay in a stalemate with your remaining civs forever, and just keep founding cities all over the map century after century...
It reminds me of Pirates! when your health went south after about 10 years and you had to wrap it up. I hated that, but I soon realized that is why you have to plan out and carry out your strategies, and more importantly, to take gambles.
But I hear you, man. My current game is at 1956, and there are three civs left but they are massive. After I sweep the French into the trashcan, I'm going back to Democracy and focus on Spaceship Production and research.
Each of these other civs have a densely packed continent, and I'm sick of my slow science advancement and marshalling tanks and jets around the screens. In short, I don't feel like starting a huge campaign with a time-bound gun to my head (no pun intended).
