my car prior to my current 64 cutlass was a 95 z28 and changing the spark plugs on that thing was about the hardest automotive task i have ever done it took like 8 hours and no its not cuz i am retarded
i am currently replacing floorpans and the spark plugs on the camaro were harder. you are right for what you gain in engine space and simplicity you lose with fixing rust and doing bodywork. i guess its just trade offs.