Without getting into that particular debate, "IF" the Computer's Output was affected by "other activity", then it would have the same impact on whether the computer was replaying a WAV file or a Lossless file
Likewise, we are also talking about non-PC Players here, like SB, Touch, Transporter, Sonos etc.........these Devices are dedicated to Receiving the Lossless File, Decoding it and Playing it......they are not doing anything else at that time
IMHO, if a User is using a computer for Music Replay, then it should be dedicated to that purpose, with all "other" activity being minimized or eliminated..........likewise, DIsc Activity should be minimized during Replay (which is what Memory Play does on the Pure Music Player)