I'm not a fan of painted necks at all, to me they look cheap, I'm afraid, even if they aren't. My B2 has one and I had to sand it to stop it feeling sticky.
I suspect painted bodies originated to cover up cheap wood or block construction, then the potential for different solid finishes evolved.
The need was never really there to disguise neck woods so most neck finishes are clear or the occasional deep stain or sunburst.