Why bother?
Because he wants to! That's the only reason that he needs.
The other reasons he listed are good too.
The big Morrel target is agood idea. I use a Bass Pro bag that's about 28" square with sheet of 3/4" plywood backup. The Bass Pro bag was about $35 on sale, but since you are switching to left hand, you will probably have a few flyers and the bigger target may be a better investment.
If you send an arrow into the plywood, be sure to check it throroughly, there can be hidden damage that won't show until you shoot it again. That's how I had an arrow explode on me.
Another tip is to learn to draw with your arrow pointed at the target. Not all of your misfires will go into the bag, but most will.
Good luck,
Allen