Halwg, you been suckered. Yes, sure, it is easy to replace an entire arm assembly. Now look at that arm assembly, times two or three blades, times the first million cars. Look at how much non-recyclable plastic waste that pile makes. It is totally pointless to have that huge pile of plastic when all that needs to be changed in the simple rubber strip. A rubber strip that takes less than 1/10 the volume and fuel to ship and store and display, as well.
You and most of the car market have been suckered into thinking the whole arm needs to be replaced. I've got wiper arms on my car (not the Murano) that are 25 years old, and still work perfectly well, despite everyone telling me "Oh you can't just replace the rubber, the arms get bent and don't work right". Yeah, bent, by gremlins in the night.
If you want to be rich and lazy and wasteful, that's what it is and as long as you can afford it, you're possibly entitled to. But next time you see a big stinky landfill or have to wait for a garbage trunk to pull down the road--remember, when you replace those wiper arms you're creating a mountain of garbage, and you're also paying a bloody fortune to do it.
Brand name wiper arm replacement? $15-25 discount. Brand name rubber strip for those cars that can use them? $4-5 MSRP. Do the math, don't get suckered.