In my experience it is not the security screening that annoys pax and crew alike, but rather it is the manner of the operatives - most of whom are alluded in the belief that they are either important, or posses authority.
Neither of these attributes are required for them to perform their basic function which is to herd humans through a process that is not really that intrusive. If the operatives left their attitudes at home the entire rigmarole would take less time.