Originally Posted by
amedias
Due to the climate here it's also not unusual for many bonded forks to suffer corrosion at the crown, normally first noticed as a bubbling paint and if left to proceed, material flaking and significantly weakening the fork. This seems to affect carbon/alu bonded forks much more than alu/alu, and is an entirely different beast to a bit of surface rust on a steel fork.
That type of corrosion is galvanic, and is common where aluminum is bonded directly to carbon because they are incompatible conductors. Water forms an electrical path between them and the aluminum rapidly corrodes where it contacts the carbon. Colnago rear dropout are rather famous for this.
I think the main thing that I took issue with your post was that you ascribe aluminum fork failures - which don't appear to be incredibly common, to the ride of the fork. But I think it is fair to say that SR Prism forks were incredibly common, not stiff, and didn't fail with any regularity - which would seem to suggest that the rule you've proposed isn't accurate.
Aluminum is not the toughest material in the world, but fork fatigue does not appear to be much of an issue or failures of older forks would be common enough for there to be a reputation. But you are really the first person I've ever heard that thinks that the common aluminum road forks are problematic compared to carbon or steel.