Why is today's recorded music so loud and so flat?

From The Death of Dynamic Range:

The sad part is that when these peaks are clipped, or “hacked off” as I like to call it, the original content and quality of the sound is lost forever. Although there are techniques to “guess” at the missing part of the waveform and “re-draw” a curved wave out of the part that was formerly a flat line, this is not accurate to the original sound; it is merely an “artist’s reconstruction”, so to speak. Thus, when aggressive peak clipping is used, the record company is DESTROYING part of the music.

[Via Music Thing]