I honestly don't think that joining ladders is a solution. It is not a solution, it is just a desperate move to be able to play outside of the lobby. Obviously there is something wrong with the system if a separate ladder is the only means how to get in a solid multiplayer game. Playing in ladders is not solving the problem (which is the easily exploitable multiplayer part of Civ 4), but trying to evade it. Sooner or later, griefers can appear in ladders as well. I have no idea why is this big effort to not see the problem. It is like shutting your eyes plugging your ears and shouting "I'm not listening!", because it is of course a lot more confortable then stepping up and trying to convince the devs that something is wrong. Even the archetypical "wont work!" attitude of some people is really amazing.
Clearly, the game is vulnerable to deliberate sabotage by players. Is this really the responsibility of Firaxis, though?
It is definately Firaxis's responsibility, given they do really strive for a good playing experience for their customers. If someone didn't notice it yet, then yes, Firaxis exists because people buy their games. They do not exist to create games for their own delight, they exist to make money. Thus I think it is in their own best interest to try and make the game enjoyable to as many people as possible. If people need to make up their own solutions where the game fails obviously because of not well done concepts, then parts of the game are not really enjoyable for them. Sirian, honestly, lets say you bought a car that wouldn't brake sometimes, or would randomly die when shifting gears, wouldn't you feel a bit cheated to say the least? Wouldn't you go to the dealer/service and demand that this situation be corrected? What if the dealer simply said: "What do you want? You can still drive it. You'll sometimes run over people, or hit a wall, but you can still drive it.", would you accept this answer? Then, after you got angry he said: "Well mister, we'll do batshit about your problem because you're too emotional about it". Sure, you could try to drive very slowly, so you don't cause an accident when the brakes give you bad pRNG luck, but definately you wouldn't buy a car from them again. The "ladder solution" or "play with friends only solution" would equal to driving only on straight roads, or driving only on the parking lot when there is nobody around. Surely that is not why you bought a car.
Your list offers no mention or acknowledgement of things done right, only complaints about things not done well enough to suit you. Once you assume bad faith on the developer end to be the cause of your woes, you might as well pack it in and go home. If you are right, then nothing you complain about will matter, because the devs won't care.
Please? Are you serious about this? The guy has bought the a product that the devs are selling (well technically its not them doing the sales), it is not the question of being nice to the devs, it is whether the devs want to get additional money, or sell only to people who will never be hard on them (but then they must not expect to get paid too much). When you're selling something to a customer, you have no right to expect them to do you service (unless it is in the agreement), it is them who are paying, not you. I can't see anything in the EULA that would state that customers who are angry are not eligible for customer service. You're attitude isn't any better then Sirkris' in this regard. For me, when I see a customer disappointed and complaining, it is a signal that something is not good in the product I'm trying to sell.
Your example of the Diplomacy screen, where your opponent brought in a friend and tricked you into a stuck position... Why would you even want to continue that game?
Again, why is the honest player forced to deal with the griefers at all? Wouldn't it be simpler for erveryone (except the griefers), to have potent defenses against such things (or simply no exploitable things).
To some extent, players have to roll with the punches. If you are going to play in open games, with strangers, you need to accept that some of them will refuse to "play nice". Just get out and move on. Any resistance you try to offer them is only going to play right in to their hands, since their whole purpose is to try and get your goat.
So I guess in real life (where you have to deal with strangers as well) you also just roll with the punches. Rarely does however such a passive approach bring any fruit you know. I'm not saying that there is a definite solution, but why not to try to be constructive and at least try to reduce exploits to the minimum?