So as to let the insects eat the potato plants. Personally, I’d rather eat the potatoes myself, so I’d plant Bt.
It’s Frankenfood… totally against the organic philosophy, but probably safer.
A very complicated question. A Bt potato contains a chemical that is toxic to caterpillers and this compound is in the actual potato and is not sprayed onto to the plants. In some ways this would prevent the need to spray for any caterpiller that may attact the plants and should be safer all around. But many people call the transgenic plants Frankenfoods and are scared of the technology and some in the organic community do not consider the transgenic plants safe or ´natural´.
You will have to ask the other people if they are uncomfortable with a Bt potato. In reality, my experience in growing potatoes, you do not usually find a lot of insect that attack them if the garden is well maintained.