It's not that simple to do a bounty program, my uninformed guess is that they are almost definitely targeting a number of jurisdictions whose laws are familiar with and/or they have some kind of representive in
This is the correct answer (we run this bounty). Contests can be legally complex, there are only so many place we feel comfortable running it from a legal POV.
you can use Algora.io (it’s open source) to cover 120+ countries for the bounty payout - it would be a fantastic showcase on our website (founder here)