if you zoom in on your file, you can see that the peaks are all square instead of round. it makes it sound harsh and muddy.

a raw sound will have many sharp loud bits that are too short in duration to make much impression on the listener, but they still take up headroom. when you use a hard limiter to smooth down those parts, it frees up some headroom and allows you to amplify the sound, making it louder. but there comes a point where there are no more extra bits to knock off, and the limiter starts to affect the actual sound. once this happens, you start to cut down good parts of the sound, while amplifying background noise.

of course you might want to do this on purpose to get a special effect on a sound, but you want to be careful when limiting a whole mix.

hope that makes sense.

cheers