??
I agree that all staff should be screened, regardless of their position. I think you will find the way it turned out in Australia with ground staff and others not being screened is a result of lobbying by powerful airports and airlines. This should be changing soon.
Complain all you want about security systems, they are never perfect and never will be. Yes there are always holes in them (both physically and because of humans) but at least there is a security system in place. The existence of a security system is a deterrent itself.
Remember what happened in the 70's when all the hijackings were taking place? This was when there was no passenger screening. What hapened after they introduced passenegr screening? The number of Hijackings fell dramatically. Screening is not perfect, nor is explosive trace detection but the xistence of it is a deterrent.
At the end of the day if anyone really wanted to bomb a plane or airport then they could do it.