The fact that life in this part of the universe uses left handed amino acids and right handed protiens is a matter of chance. In the evolution of life one form took hold and the other did not. There is no reason why life in some other part of the Universe would not be formed using chains which mirror our own. As a matter of fact there is an even probablity that life elsewhere in the universe would form from mirror image carbon chains. (If we were invaded by life made from mirror image carbon changes, we would not have to worry about them eating us. )
Well.
Homochirality of life is not likely a matter of chance. There is plenty of evidence which suggests that multiple influences from catalysts, substrates, parity violating weak forces, gamma rays, stability of complexes and so forth influence the energetic advantage of one isomer or enantiomer over another. Just because sugar forms a racemic mixture in your particular reaction doesn't mean that all reactions result in racemic mixtures.
That is good "organic chemistry humor":-)LOL!You should consider that for some text book. cheers