Is airport security a bit too extreme?

I read an article recently about how strict airport security is nowadays, but I’d first like to point out, that it is for good reasons. I don’t care how many times I have to get rubbed up and down when going through the metal detectors; if they do it to everyone then it might well save my life. That said, I’ve never understood why liquid in a bottle inside your suitcase isn’t safe, yet liquid in a bottle in a plastic bag inside your suitcase is safe. What’s that all about? I also don’t understand why a phone needs to be charged to a particular level for it to come on the flight with you, we can all get caught out with flat batteries from time to time, and we shouldn’t have to leave our phone behind because of it, should we? Let us know your thoughts.