linda, in my opinion the strong opinions reflect individuals desires to differentiate themselves from other people in a related activity. After having built a few boats with both types of joints I can confidently say that the methods are different. the results are essentially the same when the boat gets it the water. A scarf joint may be stronger by weight,by an oz. ? But I have found that a scarf joint with 4mm plywood is hard to be as absolutely fair as a butt joint on the outside. I happen to think they both work just fine.

A couple decades ago I remember folks at bike shops debating whether a 3cross wheel was as strong as a 4 cross,or whether a high-flange on the drive side really does make a stronger wheel laterally, or whether straight 15gauge spokes are as strong as 14gauge stainless,ad infinitum.

So far I've figured out that having lots of latex gloves is good and that I can't just leave epoxy messes to clean up later