I don't know, and no body knows yet! But I guess this is closely related to the direction of the Earth rotation or spinning, which is right handed! The interaction force may be due to the strong coupling between the electrostatic dipole moment of amino acid residue with the magnetic field of the Earth!!!
A more likely explanation is that the chemical structure favors the right-handed helix as the lower energy structure. However, this is not always true, since certain sequences can favor a left-handed structure called Z-DNA.
https://en.wikipedia.org/wiki/Z-DNA
There are other structures of DNA besides the common B-form, which differ in features such as the pitch of the helix.
https://en.wikipedia.org/wiki/Nucleic_acid_double_helix#Helix_geometries
If we assume that the amino acid skeleton of alpha peptide 3.6 (13) made out by stacking individual amino acid residues having identical physicochemical properties plus the direction of the non-vanishing electrostatic dipole moment of the residue coincides with the major axis of the moment of inertial then in the homogeneous and isotropic space the formation of the left and right handed helical conformations should be equally probable.
If one looks at the global Helmholtz free energy of Helical conformation made out elastic nonlinear material, which is exposed to the rotation and bending due to the helical shape, then one realize that it depends only the three parameters total length, total pitch height and the radius of helix saving the intrinsic properties such as the shear modulus and the radius of circular cross section. The sign of the inclination angle doesn't show itself. Because of the square of the torsional and bending rigidities enter into the energetic calculations. Where the reference system is the strain free straight line configuration. Similarly pair-wise electrostatic dipolar interactions between the amino acid residues doesn't recognize the sign of the inclination angle.
All these show that the left and right handed helical conformations are equally probable unless there is some outher influence on the DNA system! This influence most probably electrostatic dipolar interaction since DNA has non-vanishing electrostatic dipole moment oriented along the z-axis of the helix. The outher influence is definitely related to the spinning action of the EARTH, which is a vector quantity and its direction and magnitude are invariant quantity in space!!! unless it is disturbed by the impact of a giant meteor having sufficiently large kinetic energy.
One unusual possibility is that because virtually all natural amino acids except glycine are in an S-configuration (left-handed), the right handed helical conformations of helices are the compliment of this orientation. This does not at all answer why amino acids are predominantly in the S-configuration.
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