Razing Carthage did not turn Rome into an insta-empire. They continued to suffer from massive civil unrest afterwards and then turned their xenophobic and ultimately selfish (on the part of Julius Caesar) thirst for conquest on the Gauls.
The point of the game is not to become an empire that is as good as the Romans was, it's to accomplish something that is beyond what we can even imagine as a race. Introducing endless cycles of violence would prevent that. You may notice the Roman empire is no more, ever wonder why no one speaks Latin except the Catholic Church today?
I'll introduce a word that most should be able to understand: karma.
If you act like a tyrant in the real world, somehow, something, somewhere in this big world of ours is going to throw it right back at you, whether from inside your empire or without. Implementing such a concept is beyond the scope of the game because using such means would never result in a clear winner, unless you're going for time victory.
Your civilization begins in 4000 BC. If a real civilization started using heinous methods right from then it will surely burn itself out before it has a chance to develop concepts of human rights.
Edit: And even if it
does, the cycle of violence has already begun and your empire will be susceptible to outer or inner sources of decay.
Spend culture on a social policy that prevents you from razing cities? Brilliant! Are you not in control of your own actions?
Edit: And if you're saying, 'this policy will give a benefit but it will also prevent you from razing cities'. Then which branch would it be under? Because that would imply that the other branches support city razing. And if it's in multiple branches, which few ones are totally behind razing cities? Autocracy? Tradition? Surely not Honor? Piety?
I apologise for making this thread my mission but with every new person who posts, "Well this is dumb", I must respond with, "It's for your own good". To be realistic such features should have serious repercussions and, personally, I just want to finish a game once in a while and not wallow in the folly of humanity for hours. At first people complained that this feature is unrealistic, now they seem to be complaining that it's too realistic ("I should be able to do whatever I want in a video game!").