I do it every few months to keep the system 'clean'. Nothing wrong with it (especially if I constantly uninstall and reinstall apps). There are always remnants that remain that can and will gum something up in the future. I do this with Windows as well where I will format it every 6 months to a year dependent on usage (yeah and have to call them up to validate my key). And people think a factory reset is a lot of grief?
Factory resets are usually a last resort in troubleshooting. Generally speaking, it does clear most software related issues. Such as conflicting drivers or software. Or perhaps a corrupted process/file. Even with an uninstall, software can still have a remnant remaining behind that can cause ill effects on the device. However, there are times where a factory reset doesn't fix an issue; which sometimes points toward a hardware issue.
