The Church cannot expect worldly persons, raised in a society that teaches all manner of very extensive errors which affect the very core of personhood, to suddenly change, first, and then become Catholic. To obtain converts from this society, we cannot reject all persons whose lives, in advance of conversion, are not in accord with Catholic teaching. The Church must embrace lepers before they are healed. (Here, leprosy is a figure for sin, which afflicts us all.) The Church must find a way to reach out to persons whose lives are not in accord with Her doctrine, and embrace them before they convert.
So Amoris Laetitia is correct in opening a path for those in irregular situations, to be in the Church while they struggle with their own lives and situations, yet still receive help from the Sacraments. This issue is going to become greater and greater as the Church becomes holier while the world becomes ever more sinful. We cannot abandon persons just because they are LGBTQ+ or whatever the next issues and conflicts between Church and society might be.
Fr. Martin’s work contains grave errors. But there is nothing wrong with complementing him for the good that he is doing, in the midst of those errors. That is what Jesus did. He complemented the Centurion for his great faith, an implicit faith in the one true God, even though the Centurion was likely a member of the Roman pagan religion. He complemented the woman of Canaan for her great faith, even though she was not a Jew or a follower of Christ. She, too, was likely a member of a pagan religion.
And those who both criticize Fr. Martin and reject Pope Francis are committing greater errors than Martin is. Recall the parable of the splinter and the plank. Persons who reject the authority of the Pope, who accuse him of heresy, in contradiction to the dogmas of Vatican I, are sinning by schism as well as heresy. And then they complain about Fr. Martin. Take the board out of your own eye first, you hypocrites.