Wasn't the reason that Leo Fender originally put the ashtrays on the Precision because he thought the pickup was ugly and wanted to hide it?
I'm so used to seeing bass pickups that I don't think about it too much these days but I remember as a teenager, when I first became interested in basses and guitars, wondering why guitar pickups tend to be slimmer, rounded, more low profile affairs, sometimes even behind shiny chrome covers whilst many bass pickups are basically just huge plastic bricks with zero refinement.