Some cats are not people lovers. Your cat will get more attached to YOU though. My cat took 4 years to show real 'love' toward my girlfriend and me. For you, I'd try brushing, petting, snacks and massage. That will help build the bond for you.
For strangers....you can always try catnip, or cat toys. Give a stranger a cat toy and see what happens. If it is a stranger that comes to visit often, maybe a piece of their clothing (T-shirt) lying around the cats favorite spot might ease the bad behaviour the next time that stranger comes around.
I would not force it though. Cats are special because they are so independant and choosey with those whom they bestow their love upon.
Best of luck,