Ephraim is the focus of Hoshea's prophecy.
8:11 appears to me to be one of the roots of their coming destruction. "Though Ephraim built many altars for sin offerings, these have become altars for sinning."
Our intentions come from a human mind and heart. Both of whom are fallen and cursed. Our purposes lead to destruction.
However, only when we submit to God's commands will He do a remarkable work in us. Our intentions are still rooted in Adam's sin; but as Christians, God gives us the ability to pray, worship and come close to Him where His thought become our thoughts. He reveals His will for our lives when He wants to and guides our steps.