All I know about Mary Daly is what I read on the Internet. So, while I don't know what she taught in her books and classes, I do know some of the lessons people have learned from her life and example. These include:
The Church is evil. Maybe not the Church as Jesus intended, or the Church in the mind of God, or the Church as it could be, or the Church as a notional collection of right-thinking individuals, but the Church as it has always and ever existed in this world is an agent of evil oppression.
Two wrongs make a right. Daly's refusal to teach men, or even take questions from them after a public lecture, is excused as an attempt to show men what it's like to be invisible and ignored.
Faith in Jesus is optional. Daly was an apostate. Some of her fans ignore this, others excuse it, and some -- apostates themselves, following her example -- celebrate it.
Theology is ideology. Whoever hails a militant apostate as a great theologian does not think of theology as faith seeking understanding.
Syncretize your own creed. Daly's example encourages this in two ways. First, since the Church is evil, her disciples are free to abandon whatever they want of the Church's teaching. Second, while few have followed her own extremism, many have been happy to know she was out there and felt free to pick and choose which of her positions, and to what degree, they would adopt as their own.
To reject all in Mary Daly's legacy that is contrary to Church teaching, then, requires far more than to simply reject her own explicit rejection of Christianity.
And, having read a number of personal testimonies about the effect of Daly's teaching on individual lives, I wonder about her role in popularizing the Therapeutic Gospel, which makes of Jesus' revelation of the Father a message of feeling good about yourself.
Feeling good about yourself is good, of course, assuming the reasons you feel good about yourself are sound. But the Good News is not that you're as good or better than the bums trying to keep you down. The Good News is that God loves us and wants us all to share in His eternal life. For the Christian, psychological health is not the end but a prerequisite to preach this Good News to every living creature.
I'm not, obviously, attempting here a balanced evaluation of Mary Daly's teaching or influence -- and just as well, since I'm unqualified to do that. I'm merely responding to some of the advocacy I've encountered, in a wordier if not necessarily better way than the blanket dismissal others have given.