I don't think people are talking about war demands or gifts of friendship. I'm talking about when the AI asks for 3 iron in exchange for...nothing. I would be very willing to sell him some iron, but despite apparently wanting iron he only gives it a value of 5 each.This has never happened to me. AI can ask for support, offering nothing, but they can offer support too, asking nothing in return. This is called politics. And sometimes they ask for something, with a threatening army in my borders, that's a different kind of politics.
It doesn't make sense, the value being assigned just doesn't match his apparent need. While it does make sense for Genghis Khan to value horses quite highly, giving me 50+ gold in the ancient era isn't a good idea. This is meant as constructive feedback, overall the AI's trade logic is quite good