It's an unfortunate situation for those with the rare conditions; there's a lot more potential profit in finding a way to genetically prevent pain for billions of people than it is to cure the handful with the condition.
This one line in the opening comment rubbed me the wrong way, that some how, the pain and suffering of those billions of people is less important than the handful ill with a rare condition. It's not just crassly about profits, but it's a real ethical dilemma - maybe for the greater good, greatest bang for your research buck, focusing on those billions is a greater benefit to humanity than the small handful with an extremely rare condition. I hate making this statement because I don't want to downplay the severe suffering of those with rare genetic disorders, but I feel the issue is more nuanced than the hand waving the original post does on the trade off.
All kinds of engineering talent, organizational expertise, a logistics and trade network that spanned the Mediterranean world; were necessary to run something like the Colosseum. Those loads of wild animals(some pretty exotic) and ample supplies of variously trained gladiators don't just deliver themselves, you know; nor is building that much stadium seating with rocks and manual labor exactly trivial.(Never mind the 'let's flood the place and have a lethal naval battle' days, those are a huge pain.)
Sounds kind of like the Internet - millions of advances in science, engineering, commerce and logistics across the entire planet so individuals can get cat videos and porn on demand.
If all else fails, immortality can always be assured by spectacular error. -- John Kenneth Galbraith