Because random doesn't look/seem random to humans. The problem is that these players aren't randomizing the order of the songs, they are randomizing the next ch

Because random doesn't look/seem random to humans. The problem is that these players aren't randomizing the order of the songs, they are randomizing the next chosen song. You'll want to shuffle the entire playlist at once; or use a player that attempts to avoid this issue (Winamp would let you bias the RNG to choose songs further away from the current one, for example). If you decide on the latter, there is always the chance that you'll hear repetition, because repetition is valid in random sequences.