Are you kidding? The "vast majority" want to get married because their society inculcates within them the feeling that if you're not married by age X, there's something wrong with them.
For an orthodox girl to make a personal decision to postpone marriage until age 30 is not like her choosing to have eggs for breakfast; perhaps it isn't "disgraced," but their community undoubtedly starts asking negatively connotated questions if a girl is not married by whatever age they have deemed "socially acceptable." 
Or from a different perspective, most (though again, definitely not all) of the best and brightest get married at a young age so unless you want the leftovers you will attempt to do so as well. I won't deny that I felt the same way as well, regardless of if I "felt ready" or did not.
Either way there definitely are societal pressures to get married young.
Is that a bad thing?
I would argue that it's not.
-Even though the orthodox divorce rate is rising, it's still significantly lower than the general divorce rate, so we must be doing something right.
-The older you are (and the more experienced you are at dating) the pickier you get, for better or for worse. That's a good thing if you wind up finding a perfect match, but in all likelihood it makes you more cynical about the possibility of ever finding your match.
-As we go through our 20s we become more and more set in our ways and less willing to change who we are for someone else. Being married in this transitive time period between being a free teenager and a mature adult allows you to grow together and mold around your spouse, rather than having to mold to an established individual which is significantly more challenging.
