Ok? Not every service has to be worth it for everyone does it? I don't spend much money on skateboards to be honest but I don't see the need to ask sarcastic questions about their business model just because it doesn't apply to me.
Most people would like the first benefit more than the second. If you're a farmer, maybe you want the manure, but to most people that "benefit" doesn't apply. Is my average customer sarcastic in claiming that all my service offers is two day shipping? No. That's just the only part of the service they would ever care about.
I would bet that most prime customers are interested specifically in the shipping, so to them the fringe benefits are irrelevant.
Again - I bet you that most people care about the shipping and nothing else. That is an important fact when considering the value prime offers.