I heard on a radio interview with someone from Blink-182 that they originally thought "Adam's Song" was a bad song and were surprised it ended up being a #2 on the US Modern Rock Charts. In an environment were you only get to release "hits" it probably wouldn't have been released.
I personally like every song on "Let it Ride" by Mighty Mighty Bosstones, my favorite song on that disk is also not even one that got a video or I have ever heard played in another other place.
Not every non-hit song is crap. And variety is good. Even if you don't love every song on a disk by an artist you like, you probably do like one or two that never would have made it onto the radio. I'm kindof sad the venue to try out songs you aren't as comfortable with is sortof going away. I feel like I'm going to miss out on alot of music I might have enjoyed.