Its more tradition than anything
Trolling will work. I jig because I love the feel of the bite on the end of the line. I still cast too, but I troll also. There are days jigging when you just cant miss and it sure is fun. Mostly I jig this time of year because the fish are so concentrated in a specific area that jigging and redrifting seems to produce the quickest limit. Then we go hunt for big fish and trolling is usually our best tactic for covering larger areas. Its a personal choice. Its all good