Nobody. It seems that everyone has done this once. Some do it twice. This problem seems to occur most commonly at daycare centers in Northern countries. The reason could be as simple as the fact that a child’s first sub-freezing morning is most likely spent there.
Safety standards do not forbid metal surfaces. Daycare centers could decrease the likelihood of the problem by making sure that finger protection tubes are intact and or by applying duct-tape, or similar tapes, to the tube atop of the slide.