You are describing the ideal, of course. Not all of us are arahants yet. The Buddha allowed for lay people and lay people were allowed to engage in sexual relations even though it is not the ideal and of course not done by arahants or the ordained. From Ven. Dhammika:Individual wrote: I would never separate any kind of foolishness from attachment, the two are virtually synonymous, and never justify any form of attachment of any kind -- the second noble truth applies to all circumstances.
(from BuddhismAtoZ,com)While accepting that sex is a normal part of lay life, the Buddha generally had a poor opinion of it. He disparaged it as ‘a village thing’ (gāma dhamma, D.I,4); i.e. common, unsophisticated and worldly. He understood that a heightened desire for sensual pleasure (kāmacchanda) causes physical and psychological restlessness and that this diverts one’s attention from spiritual aspirations and hinders meditation. He encouraged his more serious disciples to limit their sexual behaviour or to embrace celibacy (brahmacariya). Monks and nuns, of course, are required to be celibate. However, experience shows that taking a vow of celibacy when one is not ready for it can be anything but helpful. Constantly struggling against and denying sexual desire can create more problems than it solves and in fact can even be psychologically harmful.
In the same way that lay people are allowed to engage in sexual relations and also have children, there comes responsibilities with that. I'm not saying parents should be obsessive, but certainly there is a greater love or attachment or whatever you want to call it given by a parent to their children than what is done to others. And this is done out of necessity and care for the children.
There was good reason the Buddha did not allow the monks and nuns to get married and have children; all of the attachments and worldly concerns that come with it. Parents can still practice the Dhamma and especially the brahma viharas, but for their infant and toddler children, a greater care is needed. But most parents will find that the practice does test them and makes them grow and then when the children pass those critical first years, the practice can even get better.