Because the question was 'Who are the 100 people who most changed the world?', as in 'who are the 100 people who directly changed the world?'. I think this is u

Because the question was 'Who are the 100 people who most changed the world?', as in 'who are the 100 people who directly changed the world?'. I think this is understood in the question. Everyone named was directly involved in the change they made, as in they made/changed/invented/came up with whatever it is they did. So what if they had a mother? Everybody else in the whole world had one too.