CAPULET Hang thee, young baggage! disobedient wretch!I tell thee what: get thee to church o' Thursday,Or never after look me in the face:Speak not, reply not, do not answer me;(3.5.3)
Capulet isn't so liberal-minded about waiting until Juliet is older when she's the one pointing out that she's too young. It sounds like what Capulet wants most of all is to be obeyed. Something else to point out: the Capulet family may be rich, but they're not noble. By marrying Paris, Juliet would have been definitely marrying up and bringing prestige to the family—something that would have resonated in Shakespearean England, when plenty of rich merchants were buying up titles or marrying into aristocratic families.