Charles Babbage - gentleman innovator
Charles Babbage appeals because he typifies the 19th century gentleman savant. Rayleigh is another example.
Babbage's distaste for plebeians and their culture shows powers of discrimination (a virtue) sadly nowadays lacking among the supposedly educated.
Maybe 'scientist' is misnomer for Babbage and some others on the list (e.g. John Logie Baird). However it fits his era because 'science' and 'scientist' were terms used differently from now. At one time theology was 'the queen of sciences'. The mantle passed to mathematics but neither is science in the sense explained below.
Followers of Popper would exclude from 'science' activities not entailing devising testable theories to which may be applied the inverse logic of falsification. General usage of the term these days is somewhat lax but not as much as in pre-Popper times.
What the named persons on the list have in common is brilliant insight which later proved fundamental to present day technology. For instance the chain of reasoning/action leading from Babbage to present day computers is shorter than that leading from the scientist Becquerel to nuclear power. Put another way, Babbage had a realisable goal in mind whereas Becquerel was curiosity driven. Each motivation is of tremendous value in its own way.