Is it about Security? Is it B******s (allegedly). Notwithstanding that there is a threat of some degree from some people;
Why are Security companies paid a fortune but Security staff not trained and paid badly?...profit not security.
Why are banned Liquids, knives, scissors, cigarette lighters etc. for sale Airside at extortionate prices?...profit, you need to re-buy your supplies etc.
Why are expensive xray machines/metal detectors used on pax/crew whilst stockists/suppliers of the shops can take goods in to sell airside unhindered?...Profit and image. The public see one but not the other and there is big big money in these machines.
Why are airport staff not properly vetted and trained?...Profit, cheap labour
Why do you have to check in so early?....Profit, it increases 'dwell time' for shopping as is the term used by these companies.
This is only about profit. If someone were to look up the food chain you will probably find that the rule makers have a 'vested interest' in the companies involved. Ministers, Lobbyists and other Government personnel have directorships and promises of the like from major corporations. If that were to stop the situation would be different. They would be chosen on merit not on who they can make the most profit for.
climb the pyramid for the answer if anyone dares