That's true. Much easier to screw up doing 40-50 landings a day with platforms in close proximity rather than just a few landings as the large aircraft out in the deep water do. Usually much more distance between them, but not always. I still don't really see the big safety issue, though. The flaring of gas was mentioned but I believe that is mostly spontaneous and can't really be planned for with any certainty. It can occur even if there is no production. At least according to the signs telling you so on the platforms.