Your logic is all flipped. The question you should be asking is simply, "Am I getting $8 worth of entertainment?" Netflix has never had a great selection of the latest stuff (even back a few years ago it wasn't that great), so if you're analyzing the value proposition through that lens, you're ignoring the actual value that it provides. Rather than asking what they don't have, the type of question that should be asked is if what they do have is worth the paltry asking price.
The more I've used Netflix, the better it's gotten at making recommendations, and at this point my queue is mostly filled up with great movies I either missed the first time around or had never even heard of at all but which Netflix recommended to me. And while it definitely doesn't hit a home run with each and every one of them, it's better at providing good recommendations than most of my friends are, so I'm getting tremendous value out of the service since it's supplying me with an endless stream of films I'm enjoying, despite it lacking the latest and greatest. But for those times when I'm impatient and can't wait to watch something that was just released, only paying $8/mo. for Netflix means that it's easy to justify supplementing it with rentals from Amazon, iTunes, Redbox, or some other service.
I find that I'm much happier in life if I stop asking what I lack, and start focusing on what I have. Maybe Netflix really doesn't offer any value to you since you're only interested in watching new releases, and if that's the case, that's fine. But if you have any interest at all in watching stuff you may have missed the first time around, Netflix continues to be an absolutely incredible deal, and it'd be a shame if you missed out on it because you couldn't look past its lack in another area.