So that they can use them as primary sources to find out the most accurate facts
Personally, I think it's because it was simple and free entertainment. Given that there wasn't a taboo around death and watching others die, and it actually being encouraged, like how it was in Anciient Rome, I'd say a lot of people would actually at least try out visiting a gladiatorial contest.
After Stalin died in 1953, the number of people sent to the gulag "<span>c. decreased dramatically," since Stalin was a primary proponent of sending political dissenters, any anyone he felt threatened by to the Gulag as punishment. </span>
B for sure if not that then A