Well yes, if you become a traitor to your country by supporting a rebellion and insurrection against it, that tends to overshadow anything else you did previously to that.
They didn’t believe themselves to be traitors. They believed their loyalty was to their State first. I don’t recall any law being in place that would label them traitors if they seceded from the Union. The rebellion began when Lincoln refused to let them secede without a fight. Lincoln wanted the Union to remain intact, no matter what it took...even war. Frankly, I can understand both sides of the conflict, but I’ve always said, that if I was faced with taking sides in a similar Civil War today, seeing what has happened to this country since 1865, I’d be more apt to support the South this time around.