The Kraken:
In my opinion the term "death trap" seems a little harsh. No one died from the incident. Normal emergency procedures, and so forth . . . Probably happens a lot less than a freeflowing regulator at depth, which is equivalently the same thing.
. . . to each his own.
...
where these swivels are to be used.
As the K noted, in a
recreational dive setting where "normal emergency procedures" may safely be implemented and the two divers may directly surface after a swivel-failure, then adding the swivels might seem to offer a favorable cost-benefit ratio.
OTOH, if you routinely find yourself 2000' or further into a cave, where a swivel blow-out might result in a significant loss of gas, not to mention the resulting potential loss of visibility and need to now turn the dive and exit the cave on some other team-member's long hose, then adding the swivels might seem to offer an undesirable cost-benefit ratio.
Many of these "does X make sense" questions depend heavily on the environment in which you happen to be diving.
For recreational diving the swivels might be the greatest thing since sliced bread. For technical diving, where resultant gas loss, visibility loss, and sudden additional task-loading after a blow-out might make exiting the cave significantly more challenging, the swivels DO constitute an additional failure point and they shouldn't be tolerated by any team entering an overhead environment.
To each their own indeed, but whether they make sense or not likely depends heavily on which environment you're considering using them in.
