I've never had to do TECH SUPPORT for a friend to get their Sansa working, or move their music to a new machine, etc; I have had to to that with an iPod.
correlation!=causation
Granted, I've never used a Sansa or a Zen, but do you think maybe this has something to do with the fact that users of those devices tend to be more tech-savvy and specifically know what they want when they buy?
Chances are, a person who buys an iPod (slashdotters excluded, of course) does so because of the ubiquity of the device; they probably don't know about Sansa or Zen.
A user who buys Sansa/Zen probably did their research and familiarized themselves with the management UI well ahead of purchasing.
The first rule of intelligent tinkering is to save all the parts. -- Paul Erlich