Should religion and caste be a factor in LOVE?

It's 21st century, does anyone remember Romeo Juliet love story. I can assume those were though times, the society was divided in various aspects. But now the society has matured tremendously in terms social divisions still these boundaries can still be seen in a typical Indian society. People gives lectures about developments but how can we be developed when we can't even improve our own mentality.

A short story-
There was a boy who loved a girl, they were happy with one another. Seems to be a cliche love story. But here's the catch they both were from different religion and caste and the lad's parents came to know about the girl and the caste m religion thing and the usual clash between the boy and his parents.

The above story is one of the most common story you'll find in a typical Indian family.

Here's my question, should religion and caste be factor in today's world? We are thinking setting up colony in Mars by the end of this decade but still we are not able to separate from our social boundaries.
If we can't overcome this mindset or settle our differences then my suggestion is that we Indians must stop calling ourselves modernized or developed.

Coming back to the story, Should the boy leave this girl because these differences or should he stay with her?