Carry-ons are personal effects and therefore one of those things the forth amendment protects against unreasonable searches and seizure without a warrant.
The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized.
So a police office should be able to walk up to you on the street and give you an invasive patdown and strip search of you and your property?
If you want police to be able to do that then you need to petition the government to go through the amendment process to flush the 4th amendment down the drain.
You realize that more terrorist attacks have happened on trains,cars and buses than on airplanes.So buy your logic if you do not like to be virtually stripped searched then you should not step foot outside your home.