I flew SFO-AMS-SFO last year on a KLM 787. I normally fly Delta and have over 2 million miles on DL/NW/KL/AF. I was extremely disturbed by the number of times the cockpit door was open on the KLM 787 from AMS-SFO. All sorts of people in street clothes were going in and out of the cockpit on the flight I was on. I was extremely disturbed by what I witnessed. I left feeling that KLM didn't take safety and security seriously at all. I will not fly KLM over the ocean in the future and will stick to DL who takes security very seriously. I only want the pilots in the cockpit for landing, not random younger folks in jeans who are there as guests.