The over-compression ("hypercompression" as mastering engineers call it) probably wouldn't have been an issue except for the fact that the version in Guitar Hero sounded so much better, albeit 10dB lower in level. With a less compressed and much more pleasing version to compare to the official release, fans feel ripped off since the CD sounds so bad in in a side by side comparison.
Hypercompression is a self-defeating trend. In an effort to sound louder than the competition, the idea is to compress the program more. Unfortunately soon or later you reach the point of diminishing returns and the listener turns it off. This was determined in the radio industry study almost 20 years ago, but labels, producers and sometimes even mastering engineers didn't get the memo (most mastering guys, at least the good ones, are against it.)
In the next post we'll look into the origins of hypercomression complete with examples.