It always looks very nice on paper but underslung loads have a mind of their own.
The first problem is getting people to get into it. With you toes toasting on top of a building there is lots of encouragement but with 150,000 tons or so of steel still above the water maybe not so much.
Once they are in they have to be pulled.off fairly rapidly or the basket will start to spin. The blurb quotes 126 knots, a 332L with six drums of diesel on a 60 ft. strop and internally loaded to 19,500 lbs. will cruise at a max 90 knots at 1,000 ft. Your survivors won't fly as well as full drums so it's going to be slower. Even if it cruises at 60 knots at 5 degrees C the wind chill means that your passengers will be feeling minus 4. How long can they put up with that when they are in nightclothes and a lifejacket?
Over any sort of distance the time saved by packing them into a wire box will be lost because of the transit times compared with winching them in followed a high speed cruise.
An adjacent rescue vehicle, like a ship, will have it's own boats to shuttle with.
OK for it's designed purpose, but no good for cruise liners.