I can understand wanting the convenience of having every song unlocked right away, but collecting items is a huge part of an MMO. Imagine if all Triple Triad cards were unlocked immediately or all minions or mounts or all gear designs. There would be no rewards for playing the game. This would make the game much less interesting and also would eat into its subscription numbers massively. Collecting music is no different from these features. Working toward a goal (in this case, getting a certain music or even getting them all) is what makes an MMO.