I don't understand why they decided to make two models out of the same engine.
There are motorcycles that you buy facing the near certainty that it will most likely outlive you, like KLR 650, or you can get a Ducati with a Desmosedici Stradale in it, where you have to get valves adjusted (major service) every 2500 miles. But given timely service, no motorcycle will last less than 50k miles, and most will last above 100 before an engine block rebuild.
Comparing cars to cars, or motorcycles to motorcycles, the logic holds though.
As you go more esoteric, you need to rebuild the engine, replace piston rings, etc. But those bikes are either built for it (off road two strokes) or have the budget for it (racing). Still don't need to scrap the whole engine.
Perhaps oil changes counts as high maintenance. It can be a bit messy, but it's quick and cheap on most bikes. More time is spent oiling chains overall though.
Taiwan has drive through automated oil change machines that suck the oil out and fill up via a tube into the filler. Makes sense especially for <125cc scooters which do not normally have oil filters.
Increasing performance puts greater stress on the engine, increasing maintenance cost and/or failure rate. If engine breaks down before end of warranty, it's producer's cost.
This is an extreme example of it.