I came from a 10 quart capacity sports car and I was putting 4-6k miles a year on it and it sat through the winter. So use is what I used to determined changing. Heavy use burns off much of the contaminates, gas, moisture out of the oil. When a vehicle sits with contaminated oil, that is not good. So I agree if I was putting 15k miles/year on a car then changing it twice a year would make sense.
While 5k may seem aggressive, that is why I use Mobil 1, from the big box stores it's cheap.
Every 'Toy' forum I have been on, oil is a main tread because it is important.