Why would Jane Eyre be considered a classic novel?

I really like this review, it's colloquial but gets it right,

You know all those 'classic' novels you read in high school? How many of them do you actually remember? Well, if Jane Eyre was one of those long-forgotten books, pick up a copy. To read it as an adult is a joy: it's a sweeping, disturbing, intense, thrilling, very romantic gothic love story, written in the voice of a very intense, almost claustrophobically self-aware young heroine. Jane is no Ophelia - she's a complicated, remarkable character, and a very strong female character in a genre that usually draws women as beautiful victims at best.

There's something for everyone in this book: Windswept castles, difficult and neurotic family members, dark secrets about tragic former lovers, good triumphing over evil, all that good juicy stuff that makes a great romantic story. What elevates Jane Eyre is Bronte's remarkable style & skill and her sharp and complex characterizations.

Trust me on this: If you don't remember it from your teens, you should give it a try now. Here is one novel that more than lives up to it's 'classic' status.