Would you quit playing if your friends quit?

Some games aren't necessarily bad, but when the friends you used to play with gradually stop logging in, the game suddenly loses a lot of its fun. In the past, we'd schedule times to run dungeons, chat, and complete quests together, but later on, when you log in, you find yourself all alone. Do you think the most important thing in a game is the gameplay itself, or the friends you play with? If all your friends quit, would you continue playing?