The main idea remains, random events in IV are different and less intrusive than City-State quests in V.
Random events are a different game mechanic and not a selling point of the series. The new city-states are integral to the gameplay for culture, for growth, and in some cases for units. City-states and their associated quests are more forced gameplay than random events and its quests.
I didn't buy CiV Clown Shoes to play "my buddy" with city-states. Deactivating city-states is not practical in a game that was built around them providing sufficient food and culture for the player's civ.
If you guys are fans of the City-States and their quests, more power to you. It's apples to oranges as pertains to Civ IV random events.
I'll also add, the random events at least attempted to be based in some sense of reality. Build navy to assert dominance and get a national bonus, Forest fire and you lose a forest tile, Gladiator gets his city's colosseum extra gold, Your religious fanatics are looking for the mountain top go find it, etc. These are some small things that give you something to do and seems more or less in the realm of possibility. I could see an awesome gladiator drawing larger crowds to a particular arena. I can see a dominant navy inspiring a nation and influencing neighboring states. Hey, forest fires happen. Random events were also based on what your Civ was doing. If you weren't running a religious civ, you wouldn't be asked to find the mountain top. If you were running a religious Civ you wouldn't always be asked to find the mountain top. Random events were just an accessory to the game.
City-States is childish. "Build me a road so you can have Food for your entire nation." "Find me Russia so you can have Food for your entire nation." "We want the wisdom of a Great Scientist. You will get Food for your entire nation." It's hoky, immature, not detailed or developed. It's for simpletons.
City-states are on a par with the rest of CiV Clown Shoes. "Who has Pointy Sticks." "Smiley Point Leaders." "Most Busy People." If they had a writer, they could have come up with some real text for those screens. It all just adds to the shoddy tradecraft feeling I get when I play.
Look, I want the game to improve. I still play it. I boil over every couple of weeks. It is a simple game though and I find I have nothing to do but grind out achievements and that irritates me.