I believe what he’s getting at is that if you’re obligated to love, that’s not real love, and that while adults can survive and be relatively healthy functioning humans without love, children when deprived of a loving environment develop serious sociological and psychological issues.

Love is not something you earn, you can’t make someone love you because you do more chores or say nice things. If you just earn love like a job by hard work or by anything else, then theoretically if you just worked harder, were just a little more attractive, did the dishes a little more, you could make anyone love you. Children, and more so babies, are unable to earn anything. Love isn’t something that you can earn like money, and the fact that you can’t expect it from someone or deserve it because of how many medals you’ve won for being the best at football makes it more valuable because someone else must give it willingly.

Mind you, acts of kindness can be vehicles of demonstrating love, kindness isn’t love itself. You can treat someone kindly and not be doing so out of love in the same way customer service can be polite and helpful but not really give a care about you.