I guess it all depends on who is avoiding which complexities.
Say what you mean.
Our firebrand opponent in this discussion only wished to see the slavery edge of a two-edged sword; I say, fighting broke out because the South was invaded and the fighting was as much about state's rights as it was about slavery. In the course of the war, the baby (republican government) was thrown out with the bathwater.
In conclusion, for the detail-disabled:
U.S. Civil War = two opposite outcomes:
Ending slavery = good.
Ending republicanism = bad.