I have been learning how to splice lines for use with kiteboarding. I understand the process of feeding the line back through itself. Most people then throw some stitches in to secure it.

Can you not just tie an overhand knot in the loose end to stop it slipping back through, then splice the end back into the main line? There would be no tension in the knot, and hence no added weak point.

Why do people stitch it up, instead of this method? Opinions please.