I'm not sure why this is being downvoted. My understanding is that it is perfectly legal to download OS X 10.8+ this way; the updates were offered by Apple for

I'm not sure why this is being downvoted. My understanding is that it is perfectly legal to download OS X 10.8+ this way; the updates were offered by Apple for free as long as you run them on a legit mac (which I'm assuming you are). The downloads on kat.cr are the same exact DMG files you would get if you downloaded from the app store. If this is not the case, feel free to correct me.