Might this be reviewed sometime 
The demand itself is perfect until this glitch is triggered, but as soon as the pre-check-in seats are taken, 99% of passengers turning up at airport go straight to any open shop franchises
Just to summarise for any new players to not confuse this with the imbalances already addressed…
- Passengers turning up via transit or carparks will enter terminal to take a seat, or wait outside for check-in to open if all the seats taken (Some will proceed to a bathroom, or a food franchise, a realistic amount). This has been the sensible and playable system since the early days of ACEO.
- If you have a shop in your check-in location, as soon as the last waiting seat is taken before check-in, every remaining passenger outside will suddenly stampede your shop rather than continuing to wait. You can verify this by clicking your shop room and it will highlight all passengers turning up as they rush to the shop.
- PROBLEM: You now have 99% of the remaining passengers turning up for check-in, surge towards a shop first, consuming all of the shop demand before they have even checked in. They are also likely to get stuck in an insane queue at the shop and miss/delay their flight.
I’d suggest experimenting with this, remove most your seats from your areas around check-in (or anywhere not in the secure zone), and watch what happens with a shop, or without a shop on the same save game. You’ll see the impacts
I am not at all complaining about the complicated and continuously evolved shop/food/bathroom demand. The issue I have and think other plays may begin to notice, is that this glitch triggers a nightmare chain reaction across airports. It’s the perfect crime, leaves no trace 
Big credit to the developers for how the demand has been improved very well over time. It’s why I refer to this as a “Glitch”.
Ideal solution - the shop demand only starts once they’ve entered the terminal (once check-in open, or they’ve came taken a seat, or bathroom/care). This is how it used to work, and this is how it still works for bathroom and cafe demand which is very well balanced.