AFAIK, light bulbs are only changed when they fail -- not on any schedule. Nav and taxi lights fail often enough anyhow, so routine replacement would be excessive, I think. Also, changing bulbs may not be "a problem" in most cases, but it does represent work that must be done, equipment that must be hired, and parts that must be ordered and stocked. All of those represent money spent (though the maintainers benefit via job security).
High-vibration areas do tend to induce early failure. The tail nav light on the A-6 Intruder was mounted on the rudder. It failed MUCH more often than the wing nav lights. I suspect the vibration on helicopters would cause earlier failure as well.