Hi,
As you can imagine if you do the same flight many times then the number of passengers will decrease a lot on that flight.
The idea is to do different flights so the passengers number can increase on the previous flight that you made.
Also, we cannot change much the passengers algorithm here. If we change it in order to have more passengers on airports, imagine the flights that we don't do so often

... It will be thousand of passengers there.
So, I will think about it, but definately we need to find a solution here. On the other day I made a flight with .... only the flight crew

...
Regards,