I think there is a confusion here about what is a battery saver, and what is a task killer.
My post history is open to scrutiny and I have often condemned task killers and provided authoritative websites as citations.
Juice Defender is not a task killer. It prevents certain functions of the phone from operating when you are not actively using the phone. In particular, Sync is decreased, so you won't always see new emails unless you manually refresh in the app, for example.
I can assure you that this tech-savvy, but non-IT, person can handle "setting up" and managing an Android phone. But there's something majorly wrong when trying to explain to noobies about checking settings and running apps, and when even I can't keep Google Maps from consuming 47% of my battery for no good reason. I don't believe that people should be required to actively manage their smartphones multiple times a day. If they do, it's a failure of the technology and no one should be faulted for not wanted to do that.
I started using JD on my Rezound as a last ditch effort to not be stranded without battery power. It has had a positive, and marked, affect on my battery life. I suspect that those that are against JD haven't actually used it.