And I imagine they want planes filled both ways to maximize efficiency, revenue, profit, etc.
This is my problem with this whole issue. We're trying to save a buck when it comes down to it. Nobody wants to pay to properly quarantine and support people who have been exposed. Nobody wants there to be a drop in airline revenue, or trade.
It really seems like the #1 thing governments are afraid of is that people will stop going to the mall. That is not really the worst possible outcome here.
Everybody wants to save a few millions dollars by not treating problems like this at the source by applying "overwhelming force." However, if things spiral out of control then we'll all end up spending 10s to 100s of billions of dollars dealing with the resulting mess. This is the US healthcare system in a nutshell - we'll spend $50k on a hospital trying to deal with some acute medical problem suffered by a homeless person, but we won't give him a $1k/yr place to live where he wouldn't develop the problem in the first place because that would just be rewarding laziness or something.