Why doesn't hardware have changelogs?
Perhaps I've been using open source software for too long, but I like to scan through the changelogs (a log of changes that the authors have made before releasing a new version) to see what has changed. This can give me hints to new features to checkout, or changed behaviour that it would be helpful to know about.
But hardware (and closed source software) typically don't have changelogs. An example is my Brand New Replaced Under Warranty D-Link DGS-1008D. The old one was hardware revision C3. The new one is C4. What has changed? Will it not brick itself like the old one did after a years usage? Is this one going to be faster because they've improved the code or silicon in some fashion?
I'll never know...