I have seen a bunch of threads on here with people complaining about that bag check and secondary screening at WDW. I've read people being upset their wallet was opened, people upset to walk through a metal detector, etc
I was selected twice for secondary and it added 8 seconds to my park entry.
It doesn't appear random, they pick whoever is coming through bag check at the exact time the metal detector is open. There was never a line of people waiting for the metal detector.
As far as bag check, look at every pocket, zipper, pouch,etc. I have my family and take the safety serious. Obviously Disney does as well. I'd rather they search everyone well and find something opposed to a half assed search and something getting through the line.
It's not that bad
Some guards are more thorough than others
I am glad they have it the way they do