Hey Ahriasre,
Firstly thanks for your kind words, were really glad to hear you enjoyed the experience :D our goal was to make the games end feel more realistic and open relevant to the situation, so I'm glad that came across well!
The audience are fully aware of the stars captive state, for them it's part of the thrill.
As to the why it's allowed, and why various world governments donate their death row inmates to the show, well.... That's a story yet to be told.