At absolute worst estimates of taxes and costs incurred, they more than doubled their money virtually overnight. And that’s just on the jackpot, not counting the smaller prizes.
There was indeed a risk of sharing the jackpot, but again it’s just sharing the jackpot, plus the smaller prizes…it’s probably likely still profit making until there are 2 or even 3 other winners.
Saying this is a silly venture is like saying it’s silly to play a roulette wheel with 45 black numbers and 5 red (and either colour pays 2x), because you could bet on black and still lose your stake.
Or by “silly” do you mean dishonest / dishonourable?