I think he's confusing shows/videos that are Prime eligible and those that aren't.
Amazon has pretty much anything you could think of in their streaming library--basically anything you could also buy the dvd/bluray for. But, like Netflix, there are legal/licensing limitations on what they can provide for free.
Netflix chooses to omit all those videos from their streaming library. Amazon lets you pay for them if you want to watch them anyway. And, with a Prime account, the pay videos are still cheaper than you're going to find them for anywhere else.
For example, the day the STiD was out for the early online release, I got it right at midnight for $12.
Non the less, from just the shipping, the discounts, and the like the $80/year almost pays for itself before even taking the prime videos into account.