“Why didn’t Lincoln share the same feelings about Southern secession?”
Because he was a hypocrite.
I don't know about that. Lincoln said being inclined and having the power. The South fell short in half of those requirements.
Boogieman: "Because he was a hypocrite."
No, because in early 1861, the Confederacy provoked, started, formally declared war and sent military aid to pro-Confederates in the Union state of Missouri.
Lincoln merely did what the US Constitution required him to do: defeated the military force attempting to destroy the United States.