YOU BET
I have, and loved it, on both my newer boat and older boat. The answer to why? Simple to keep your good finish from becoming a "failed finish" It seals and protects the existing gel coat. It will not thin the gel coat like compounding and abrasives will. Therefore you have a thicker gel coat well into the life of the boat. Too much abrasive will remove the gel coat over the years. If you are only going to keep it a few years don't bother someone else can worry about it. I would however do all I can to protect my boats finish. Use it you won't be sorry.