There is another possibility, but I think sharptonn is closest to the mark. Some people are simply more acidic in sweat and body oils, than others. The more-or-less neutral at room temperature oils in the fingerprints may have become just slightly more aggressive in the heat of the water. Sometimes to get an acid to cut faster a little heat can do wonders. In this case, a surprise. I agree that something more aggressive for a polish may be needed.

And hopefully that chip I see is an illusion. Hope this helps. Next time you try the hot water thing, use a degreaser first and don't touch the bare steel again until you're done.