Like many people have pointed out, the main difficulty of older games are their bad and dated design choices. I tried Starcraft and it was kinda hard to beat because the game thought it was funny to give the enemy a basically impenetrable base with just about every antiunit in existence. The only way to get through was to build a massive army of troops and send them to a small spot of non AA guarded area (the base was on an island) and just overpower them with a force of ridiculous force.
Another example of bad design leading to challenge is GTA4. Though not old, I found that one of the hardest missions of my life in any game was one where you have to kill some cyclists. The games gives you a motorcycle and tells you to shoot the cyclists will riding it. Now anyone who has played the game can say that shooting isn't too easy. They can also say that driving a motorcycle isn't very easy. Now combine those 2 and we have a retard cocktail. And there is no chance for you to use something a bit more practical against the cyclists, like say a fucking truck, since the game fails your mission if you get into any other vehicle.
Multiplayer games usually come down to 2 factors: skills and technical things of the game (map design, bugs, lag). If you lose, you pretty much lose because the other player is better. Sure, he maybe be better in sitting in a corner in front of your spawn area, but you could have easily done the same thing. Calling others a noob if you are better than them is a bit impolite though, since noob refers to beginner. Even if you are better, it doesn't mean that the other player has just started playing the game (unless they walk into walls and ask questions like "which button makes the gun fire").
