Especially since the Amiga version just a very very shoddy quick port from Adlib to MOD.
Actually, the Amiga and PC versions of Lemmings were developed more or less concurrently, with the Amiga version happened to be released slightly earlier.
As far as technology goes, neither port really took full use of the available sound technologies. The adlib version in fact doesn't need to be limited into using only 3 channels out of the
9 available for music. If anything, it would almost seem as if the legacy of 3 channels originated from the Amiga version.
Together with the fact that a good number of Lemmings music are simply re-arranged "classic/folk" tunes with no copyright restrictions, instead of originals, it's clear that music simply isn't as big a focus as it could be when it comes to the original ports of Lemmings. Also, considering that the Atari ST version was I think also developed concurrently, and that the PC version also supports Tandy with its more primitive sound support, it may simply boil down to a case of developing for the least common denominator.
So yeah - kind of frustrating when searching for this soundtrack, to hear people "liking" the Amiga version so much.
Haha. Relax, I think this is just a simple consequence that there was much more of a "MOD scene" with the Amiga in general, due to a number of technological advantages. When you already have an environment where it'e easier for people to rip music off of a game to be played in other contexts, there's bound to be a selection bias favoring the number of people who'll talk about the Amiga game music compared with the PC, even if it might well be the case that there were actually more people who first played the PC version.
The simple practical fact is, recording and sharing the PC version of music is pretty much not practical for the typical user until the days of Windows and DOSBox and widespread adoption of sound cards with full digital record and playback capabilities, plus the development of decent compression like MP3, and technologies like the internet (you'd be hard press to fit all the MP3s of the PC Lemmings music onto a 3.5 floppy!). Unlike the Amiga.