Just curious as to why this is popular.

Currently on a BA Holiday and not sure I will again. Although with only 1 night hotel, I don't qualify for this offer.

Having zero options to cancel in the final 3 weeks isn't good compared to regular flights and it seems that BA doesn't want to know very much with regards to questions as you don't book via them, you used a travel agent etc

Yes it is a good offer, but not sure if the risk is worth it as we have no idea if borders will be open erc. and need to rely upon insurance.