A Free Man said:
The problem most people have with multiplayer oriented games is the price.
A very popular example: CoD vs TF2
Both are multiplayer focused. Both have about the same amount of multiplayer content. CoD has a single player, albeit a very short one that really isn't that good, whilst TF2 doesn't.
Here in Aus, TF2 was $20 when it cost ANY money (Now it is free), CoD starts out at $100.
If you are in America, fine, 20 vs 60, but why is there that much of a price difference? The single player in CoD is in no way good enough to justify $40. Maybe 10-15, but that is still kinda pushing it. Why, is CoD sold at the same price as games with FAR more content than it? (Try Mass Effect as an example, which atm over here is far cheaper than CoD, and has FAR more content).
Multiplayer only games don't get criticised as much if they charge an appropriate price, and advertise the multiplayer instead of the singleplayer, yet very few do. This is the main problem people have with multiplayer only games. I will once again bring up TF2. Do you see many people complaining about it here? No? But its a multiplayer oriented game! It didn't even have a single player! Why aren't people complaining about it? It charged a reasonable price, and didn't try to sell itself as something it wasn't.