It would be the norm to expect the positive terminal to be protected by some form of cover, most battery manufacturers supply the battery with such. As for the earth terminal then this would not be the usual expectation. Mentioned earlier was the fact that any live cable touching the bodywork would cause a short with the bodywork being grounded is quite correct however, this is why the circuitry of the vehicle is fitted with fuses. I am an electrical design engineer, no matter what you are designing for 12volt, 24volt, 240volt, 415 or more the fact that you design for fuses within the circuit is to protect the cable. If it does short then it should blow a fuse and NOT sustain any heat by prolonging the short that may cause a fire.
In short, I would investigate purchasing or making a cover for the positive terminal.