I think it would be great to have a cheat that makes guests never think of leaving the park or at least put it as the last priority.
In the current state guests will not do anything except wandering around as soon as they are 'leaving the park.'
I hope guests respond to their needs nonetheless: hunger, thirst, toilet. So that they use the shops when they are actually trapped.
It would be fun to see an island with only a couple of shops and ATM for a constant income
If it isn't for those extreme scenarios, it'll still add to the fun of building shops as they will be used more actively, especially in larger/complex parks.