To give thanks FOR all circumstances is to say that the situation itself (rather than what might arise from it) is good. We risk calling good what is evil.
And when we do this, we skew the vision of God’s creation and recreation. We present (to ourselves or to others) the idea that the world as it is, with all of its bruises and scars and brambles and deep pain, is what God intended for us. We turn God into a cruel or distant being who wants us to say thank you for injustice, inhumane suffering, and evil.
These things that are so far from the vision of shalom in scripture shouldn’t be celebrated. They should be named for what they are.
The Psalms, the prayer book of the Israelites, is not comprised only of prayers of thanksgiving, but also prayers of lament. They give us space to complain when things don’t line up with the goodness of what God creates.
By all means, look for things to give thanks for in the hardest seasons, in the biggest instances of injustice and evil. Look for ways that God might be working, that God might be meeting you in the midst of the pain. Cling to the hope and the promises and the new creation as if your life depends on it.
