Don't you fellas have enough toys to play with as it is?
I feel this device would be useful. However, on a pier with a bunch of other anglers would probably not be ideal. Just as a single lantern beaming it's light onto the water's surface at night draws every angler within jigging range, so would this novelty. Don't see how you could successfully hook a fish without the possibility of it taking you around the line attached to this thing-of-a-ma-jig. Also it could be difficult to fish more than 1 rod "stress free." Sure there's always the possibility of hooking up with both rods at a time without radar/sonar intervention. But to know for sure that there are a lot of fish near two or more of your lines would definitely rank up there with strong regular brew coffee. Would give me the jitters for sure. Now for anyone who's a thrill seeker, this is right up their alley. For pier applications............ it's definitely not for the over 40+ crowd. At least that's my opinion. Would make a terrific gift for one's child or grandchild though. And of course, the purchaser would have the tedious job of helping em figure out how it works. ;-)
Now putting it to use while in a boat, that's a whole separate matter. A single angler would definitely benefit from such device.
Still I think it would take most of the relaxing aspect out of fishing.