Sonia,
There is also an engineering explanation (though I am not discounting the retracted storage issue).
During touchdown, the "truck" containing the four tires can either strike the ground "heel" first as does your foot or "toe" first as does the 767 and many other jets. I bet there is an engineering explanation that allows the toe-first truck to better absorb the landing impact to provide a softer touchdown. A heel strike may slap the front truck down harder exacerbating a firm touchdown.
Hispano Suiza (or their newer namesake) built most of the gears out there. Find them on the internet and shoot their engineering folks the question.
Cheers,
PT
