That is silly.* But you can do what the mountain bikers do and get frame protection tape. I just bought a roll of "racer's tape" Not cheap, but then again neither was the bike. I generally only use it on places where I am concerned about abrasion though. In my case, that is my heel against the chainstay (a new "feature" of disk brakes I guess).
I do use a seat post mount fender for my butt - but that doesn't protect the bike. We could help you better with a picture of your bike, but not knowing that - SKS race blades are great - SKS makes a whole variety of fenders
*I'll say that people who ride Gravel King Short Knob tires make a butt load of noise going down a dirt path or rail-trail. Never seen a tire throw pebbles like that one.