The Colosseum fell to pieces because an Emperor decided that he felt for all of Rome that it was amoral.
Then Rome got boring and the empire fell.
I for one think that Gladiatorial games should be re-instituted for those who wish to participate, and I would be part of the crowd, cheering and roaring.
None of this wrestling and boxing crap. Ultimate Fighting Championship comes close, but still not up to B.C Rome glory.