I found the review incomplete of these games because there is no reference to the either the vocals or the drums.
Furthermore I think many people on here are forgetting a couple of things involved in making a Rockband/Guitar Hero track:
1) Some songs just aren't compatible with the game. If there are major changes/errors in rhythm, making a game that follows along with it can be extremely difficult and will ultimately disappoint people.
2) Not all of the old classic songs are conveniently laid out in multi-track format. A lot of the old Beetles songs for instance had all instruments and vocals on two tracks only. Going back and separating all of that out into 4 distinctive tracks can be challenging and expensive (and sometimes close to impossible). So many of ya'lls assumptions that some mere software developer can make releasable DLC of any song in only a couple of hours is total ignorance. Furthermore this kind of investment to remaster the sound would not warrant some tiny 3 or 4 dollar DLC charge.
Finally, these games are not just for wannabes. I'm a real drummer, not terrible either, but I still love these games. If you can find me a backup band that can play a Slayer song in perfect pitch and Rhythm at 11PM on a Sunday night. Maybe I won't want to play this game.