Maybe because they're probably 50+ years old and have been torqued who knows how many times? And since we're talking drums they're only 7/16" studs to begin with? Unless you're the original owner they have an unknown history possibly spanning decades where they were overtorqued, undertorqued, run through how many potholes or into how many curbs?
The opposite argument works just as well. You've got them out, why wouldn't you install new ones?
