There was a discussion a while ago on RBR about corroded handlebars.
So I corroded my 2nd handlebar
Handle Bar Corrosion

I think some individuals are more prone to corroding the bars than others. Of course coastal environments can be damaging to bikes too.

For some reason indoor trainers can also be hard on bikes, as sweat may drip more than evaporate.

As mentioned earlier, 6061 aluminum is a marine grade and should have reasonably good corrosion resistance. 7xxx aluminum can be made thinner, but loses the corrosion resistance. So, new lightweight bars might be more corrosion prone. The OP's bars puzzle me a bit as the old aluminum should be good, but perhaps Sakae took some shortcuts.

In the RBR thread, it was suggested that the person who was destroying his bars try Carbon Fiber instead.