Daughters Should not be Kept at home for long - did anyone tell you why?

A common scenario within many Indian families:

Family with daughters: My daughter is not married yet, she is studying/wanted to work or pursue her ambitions.

Idiots/Know it all within the Indian society:
Apadi lam iruke kudathu, ponnunggelam vithule vechiruke kudathu. (shouldn't keep daughters too long at home)

My question is why can't you keep daughters too long at home?

because they have expiry dates?
because they get spoiled like vegetables/low shelf life?
because they are a burden (in which way when they are a burden when they are self-sustainable?)
because random Indian guys will not be able to find life partners?
because after 30s, women will have problem conceiving (nothing to do with Indian men and lower sperm count?)
because that's how it is done for generations?
because daughters are supposed to live and slave out at another home?

See, marriage is an option and if girls choose to marry late or stay single forever, it shouldn't even concern the rest of the community members. You can't expect women to simply marry and have kids with random guys whom they can't even connect emotionally in the first place. And what will you achieve by such weddings? Mission completed? Parents' job to marry off their daughter completed? Is that what the society wants to achieve?

You will see a bunch of morons who think they are entitled to advise others on how to 'get rid' of daughters through marriage. Marriage should occur only when two individuals mutually decide that they wanted to get married. It shouldn't happen by forcing two random strangers simply because they have reached the so called 'marriage age'.