It may not be the design that's at fault, the biggest killer for aluminium is the stuff thats in "muck off" and the like, it's brilliant for cleaning, but if the anodising has worn, exposing the bare aluminium, then it will corode.
It's simliar to the chemicals that are used for swimming pools, people who have stored their aluminium bikes in the same place as these chemicals have seen their bike almost disolve :shock: