From what I understand, having all routes in 0.5 freq are both illogical and unrealistic...
The profit cannot simply be counted on in one single day.
If you want realism, then you can't have 0.5 flights. Even for the long haul flights, since that aircraft has to get back to your base. If you only have a oneway flight, then your aircraft is stuck at the destination's airport. If it's going to flyback, then you might as well load it up with passengers and bring them back to your destination.
Another realistic option is to fly your aircraft from one destination to another. So, I could have my flight leave Toronto bound for Ottawa and then leave Ottawa for Montreal, then back to Toronto.
I have been on flights that would stop in a city to pick up more passengers and refuel while continuing on to my destination. I once flew from Trenton, Ontario to Saskatoon, Saskatchewan where we picked up passengers and refueled then continued on from there to Quadra, British Columbia.