I don't believe it is entirely arbitrary. Just as there are categorizations of machine, turing machine vs push down automata vs finite state machines, which det

I don't believe it is entirely arbitrary. Just as there are categorizations of machine, turing machine vs push down automata vs finite state machines, which determine their ability to solve certain problems, there are differences between categories of algorithm and their ability to solve certain problems. There are many "learning" algorithms beyond what is popularly called ML today but they have in common that they use information about their own success or failure to inform future results.