This will depend on what you believe is “truth”. On what you believe is good.
For Catholics, Love, Goodness, Righteousness are not “subjective”, meaning they do not depend on the person, they depend on the one that is Alpha and Omega, the Beginning and the End.
The problem of homosexuals adopting relies in their values and what they consider right, what they consider good. Because those are the values that the kid will probably be given as truth. And this ideas go against everything the church teaches. Remember that the best “good” for a man is God, in the means he steps away from Him, he will lose Truth, he will lose “ True Life” and the Way.
That’s why I would think that it isn’t a good idea to make it a normal thing (an option). Catholics cant accept a marriage between homosexuals, Why, because a marriage for the church needs three aspects, but remember that marriage is for the sanctity and holiness of the couple, because the point is getting to God :
-First procreation (existential order)
-Second the personal union of man and the woman.
-Third the proper direction of concupiscence
That’s the correct order although the three must be present.
Apart from this you have what the Catholic Church states as the meaning of love and its integration In the relation of a man and a woman. A man and a woman can only have sexual intercourse in marriage where the love (if built correctly) is fully mature. When this love is fully mature, the sexual intercourse between them, evolves to a personal level where there is no using. The only way that the sexual act can stop or cut out its utilitarian property, is the common end of procreation. Then pleasure stops being the end of the actual act. Why is this important, because a person cannot be used as tools for an end, as persons are ends by themselves and because of the nature of their specific creation. We are created under the image of God, where everyone has the final end of God. (We are top ends, this means that using for pleasure or for anything else would be degrading, to the essence of persons).
I believe the Church understand that two homosexuals can “love” each other, because Gods commandment to love is universal, so that’s not the problem (love thy neighbor as you love yourself, or the complete one: love others as I love you). Where the problem resides is that bodily love and sexual love, the one needed for procreation can only be performed by persons of different sex. This type of love is only permitted between a man and a woman, if not, the act or the sexual acts are mainly for pleasure leaving pleasure as the final end. This is the same case as in masturbation or any sexual act, even heterosexual ones, were both sexual organs do not join, and the hope of procreation is not possible, or not given a chance. It would be “using” as experiencing pleasure because of the other, or because of stimulation.
An objective finality of procreation is to unite the two persons of the human species (male and female), this goes with what the Gospel states of the creation of the world when God made Adam and Eve.
Homosexuality in a sense cuts the existential property of marriage and with it, it cuts the union of the male and the female person, and “states” that adam or eve for “me” is not that important, tossing the creation that God intended for each other, away.
Homosexuals (“acting ones”) cannot give a child the full grasp of humanity as they are one species short, they can give him “love”, but not the love that God intended, the one that comes from adam and eve.
Truth for a Catholic lies in God, and goodness lies in God. Therefore if you are not doing God ways you are doing bad things. This is important because the first commandment is to love God first, this means to deny yourself for His ways, because you believe that only in His ways you will truly do good. Then if you go against God (acting homosexuals in their unions), this means you have no problem going against His ways and stating that, that is a correct way, because that’s the way I like it. Then you are saying that good is only good if it “feels good” to you. This is something that a Catholic can never say it is correct. Understandings can only begin at the “Beginning and the End” for one that has faith (of course. So that we give due respect and Justice to the Creator, the one that is True goodness, true righteous, true love).
That’s why I started that this question will depend on what you believe to be truth, on what you believe what is good, on what you believe is the “Beginning and the End”.