Why do physicists find naturalness as some important feature a theory should contain? Since the choice of the theory's parameters is quite abstract (or can be experimentally determined), what's the reason a constant that you put by hand and can take values from 0 to "infinity", be constraint to take values near to some other constant of your theory? I know they say that naturalness is an aesthetic argument, but some people seem to strongly believe in its power. I hope my question makes sense? If not please allow me to retry.