Nope it is far more simple than that. They don't want a swim. Both the Shark Tunnel and the Swim Shack are Attractions. The guests, and game is programmed with random Needs for Hunger, Thirst, Bathroom, etc. Attractions are Fun. Guests usually do not want two fun things in a row. Or two restaurants in a row. So the setup above needs exits to allow the guests to choose to go and do other things.....and to allow peeps to get to the shack to go swimming rather than visit the Shark Tunnel. They will not do both. They may come back later and do the other one after seeing animals or eating, etc.