its all about who has the "loudest" album. Mastering engineers are pressured to compress (or in this case, I like to call it SMASH) a signal until it is just under the point of clipping.
If you were to take a CD recorded and mastered with today's standards and sent it direct at line level to a vinyl "cutter", the machine would actually cut a hole through the vinyl leaving nothing left of it. Its all about dynamic range. All of the dynamics and environmental feel to an album is LOST after this. I posted some time ago somewhere of an example of what a clip sounds like raw and then what it sounds like after it is mastered by today's standards.
It is ridiculous, but can't avoid it. Its a trend that will hopefully end at some point in time.