And while it's true that few ("normal") people still live in Venice, it doesn't follow that what remains is as worthless as Disneyland. Nobody lives in the Louvre, and it's still a culturally significant place!
The idea that buildings in Venice are layered, with newer ones built on top of older ones when they succumbed to the water seems to be mythological.
Venice isn't going to do cotton candy. Picnicking on the streets will get you fined, and in some cases tourists have been thrown off the island for such uncultured behaviour.