I wouldn't be so quick to blame the rod, as I would the excessive effort this caster seems to use. Joan Wulff's standard casting motion involves a bit of "drift" in the arm movement at the end of the casting stroke, and she uses soft sticks. My wife puts way too much effort into casting, and weird things happen. On very narrow streams, I don't spend too much time trying to correct it (although I do make an effort), but on larger streams, it's addressed immediately. In her case, she gets excited about fishing
takes a back seat....
If I'm targeting a fish, casting becomes even more important, but I can understand. After 15 minutes of demonstration and relaxation coaching, she goes back to throwing nice tight loops.
Casting physics wasn't something that interested me at all until 8-9 years ago. As long as I could fire off 25-35 feet of line without hooking my ear, I was happy. When I came time to show my son how to cast, I suddenly realized I was almost clueless!
My wife's latest bad habit is to make a single haul on the back cast, and then let the line she hauled down go slack on the foward cast. I won't say it makes me crazy, but I do know that practice makes perfect, and practicing bad habits just makes them part of the routine. More bad habits are added to help compensate for the previous bad habits, and you eventually have a real mess.