A plain blade is actually more versatile than serrated, with some proper sharpening technique. If cutting mostly rope, or other things where serrated is nice, sharpen the blade to a very keen edge (fine grit) - then push the burr of the blade forward over a medium grade stone for a few passes. This creates micro-serrations which grab rope or fabric very well.
But then, if you strop the blade several times, or sharpen back to a finer grit, you're back to a keen, kitchen-friendly edge. In comparison, a half-serrated blade is clumsy for food prep or fine whittling.