what there is that will draw a person to like a specific genre.
I have a hard time thinking of a decent answer to this question, but I think it sometimes depends on how open you are to music as a whole.
If music is just a secondary thing in a person's life (eg; parties, clubbing, to help study, etc), that person will tend to like more mainstream stuff. That's not really a good or bad thing at all.
If a person listens to music because he/she's interested in how sounds work, or how progressions develop, or for subtleties, or to experience a wide range of moods, etc., that person will be more receptive to a wider array of genres/artists. (Perhaps more "underground" stuff).
Depending on your personality, you may find a certain genre often has more tracks that appeal to the subtleties, or progressions, or sounds you find most pleasing. And of course, that becomes your go-to genre.
Someone who likes rock may like electro house as they both often share high energy. Or an R&B fan might dig progressive house for a more mellow feel. And maybe if you're generally more open to music, you could be a hip hop head bumpin' trance, or vice versa.
I dunno how good of an answer this is, but everything is subjective, that's for sure.