halo quickie question

hi
i am the proud oner of halo(£30 at game)and its original.i did a easy 1 to 1 copy cause i like to keep my game mint condition. my question is y do peeps keep asking for cracks when all they need to do is a 1 to 1 copy. im no einstien but surley it makes sense to do a 1 to 1 rather than cracks,or am i missing something(apart from the odd brain cell or so).plz b gentle after all im a newbie