Hare Krishna dear Devotees, please accept my humble obeisances!
All glories to Srila Prabhupada!
It is true every girl should be married and protected from other men.
But sometimes because girl is little bit serious in spiritual life it is considered as a disqualification;
People think that person with stronger spiritual values are not capable of performing their material duties. Where as they do not know that indeed such person is more devoted to his/her duties knowing that by doing all that she/he will please Krishna.
And that, they decide seeing some other examples in life.
So if Devotees don't consider getting married to a spiritually inclined girl what if girl gets married to a non Devotee?
Because not being married is a dangerous choice.
Thank You so much!
Your servant, Mohini Madhavi Dd.