But 24% of total hospitalizations were people in their 40s or lower!! There were almost as many 18-49 as 50-64!
One is a group covering 30 years, and the other 15 years. And there are still more hospitalizations in the 50-64 than 18-49. The point is, if you are over 50, you are higher risk. If you are under 50, you are by no means "safe" or "immune" and should definitely be taking precautions to make sure you don't get sick. Under 50 still accounts for about a quarter of all hospitalizations, and I think we can all agree that under 50's are less likely to go to the hospital unless things have gotten bad or that have other underlying issues.
My point is, setting the line at 50 does not take away from the severity of the situation for the people you're trying to convince to take this seriously. Setting it over 50 (at 65) may make them disregard the severity.