As some people have pointed out, the conclusions of the survey are flawed as it is comparing aspirations of children today with the actual careers of their parents and also assuming that in the past children wanted to follow "popular careers" of the day. It would have been interesting to compare parents' aspirations as children with those of their children, making allowances, of course, for the appearance of new jobs, e.g. in computing.
I know at one time I wanted to be an archaeologist and a racing driver (there were only 10 or 12 GPs a year then with racing finishing in September at Monza and not starting again until the Spring at Monaco, so there were a good few months available for archaeological digs). I ended up, after working in business for a short time, as a teacher and then moved into examination administration. How did that compare with my father's working life? Well, he started working in industry on radio development, moved into education in the RAF in the 1930s, then transferred to developmental work in the RAF on "bending" the navigational beams used by the Luftwaffe and after the war went back into teaching, ending up as a headmaster. How did that compare with his father's working life? Well, he joined the Royal Engineers as a Sapper, gained a commission and transferred to the Queen's Own Royal Madras Sappers in the Indian Army. Strangely enough, his father's career (my great-grandfather) had largely followed the same course! So not much of a pattern there, apart from the case of my great-grandfather and my grandfather, and that is probably largely explained by the strong tendency for sons to follow fathers into the armed forces or other uniformed organisations, e.g. police and fire.