How lovely for those ancient Romans to have such an extraordinary venue for entertainment, right? Except here's the catch. The "entertainment" for the most part was completely and utterly barbaric and yet normal, everyday people attended.
"Hey Grandma, put your wrought-iron dental implant in. We are going to watch gladiators fight to the death."
"Kids, for the Cth time let's go, we are going to be late for the execution."
"Domitia, I have a great idea for our first date! Let's go watch some exotic animals get slaughtered."
(Of course, Romans being Romans they made sure that the executions of condemned people were conducted in "mythologically authentic ways, such as being mauled by beasts or burned to death."* Kudos to them for their love of literature.)
Boy, did I leave that Colosseum depressed (and thirsty), but at least I consoled myself that for the most part as a species, we've evolved.
Case in point: For every horrible person there is like dentist Walter Palmer gaining pleasure out of killing a beautiful, endangered animal for sport, there are tens of thousands outraged. That brought me comfort. Except when I started reading some of these posts, my faith in humanity waned rather quickly. Many people called for the skinning alive of the dentist. Others suggested that we feed him to the lions, a la the Colosseum. Still others thought it would be peachy to shoot him with a bow and arrow and watch him suffer a slow death. Believe me, I want this guy to be punished, just not in this way.
So really it seems we haven't evolved at all. The only difference now 2,000 years later? We can catch our reactions to such events with a selfie stick and smile.
*Source: Wikipedia - perhaps next time you ask, I will finally donate to your Wikimedia "Foundation". (Though, if Thomas Hobbes is right, my "nasty, boorish, short" nature will probably impede me from doing so.)