The reasons may seem obvious: domineering man, seemingly demure young woman with strong opinions; Gothic architecture; horrible relatives; angst-filled backgrounds; fire; passion and so on...
However, I suggest that like with fantasy tropes, romance tropes can't simply be thrown into a bag and tossed together. Something else has to be going on to invite reader investment.
With Jane and Rochester, the reason is...Jane and Rochester are both kind of weird.
Jane is skinny and taciturn. She isn't very womanly though she adopts various feminine traits when necessary. She is passionate, which she learned when she was younger to damp down. Like young Victoria, she has an inherent sense of her own worth though she is cautious when faced with excessively confident people. She adores Rochester. She manages him very well.
Rochester, as I've mentioned elsewhere, is a beta trapped in an alpha body. He is sensitive, uncertain, self-conscious, intelligent with an off-kilter sense of humor. He has no clue how to woo...anybody. He thinks he despises some people but he probably doesn't really (he wants badly to be liked). He tries to maneuver Jane into confessing, which is frankly a weird thing for a man in his thirties to expect from a young woman of 18ish.
At two points--with St. John Rivers and with her inheritance--Jane has the chance to be "socially proper." She gives up both extremes (extreme humility, extreme social standing) for a weird guy with bad eyesight and a bombastic personality. Rochester and Jane have their friends and family and each other. Nothing else matters.
In high school, they would be the gal and guy who float between cliques, the ones who don't totally fit anywhere.
But they fit each other!
