Doesn't matter if they chose the lesser, inferior technology - it's ubiquitous, commonplace and easy to use.
SCSI was superior to IDE, and IDE still won out in the long haul. Joe Lunchpail found SCSI ID's and terminators confusing compared to a simple master/slave jumper.
In the world of commodity devices, the best solution rarely wins out. The common man uses what works, the power users have more suitable options.
I'm no fan of the slow speeds of USB, but I've never had a lick of problems with USB devices, even on my Amiga systems.