why null is safe?
because the players made a big safety net around their homes in null sec , that includes capital ships 24/7 ready to fight the enemy , big healing ships (faxes) , intel channels that identify the enemy wen he is several jumps away … etc … etc … etc
to have this you will have to join a null sec alliance , each one of them have different rules but the bigger ones have new guys recruitment corps
high sec is "safe " because people has to kill you before concord kill them , but gankers use a lot of high damage ships to circumvent this difficulty in a lot of creative ways , concord is in the game to punish not to protect so most of the time one would be more safe mining under null sec alliance capital ship umbrella than in HS . plus the CODE doesn’t operate un null
why dont new players start out there?
nowadays they practically do . you see lots of clueless noobs in null , because their soft bodies is devoid of the thick carapace that older players have, they enjoy the services and protection of null alliances while they suck the tits of undeserved isk and get fat and rich , unfortunately that pleasure and nutrition come with the cost of the noob soul