And oen of the reason for that is, that people stopped playing franchise because it isn't really a community expierience and because people are relaseing to the wild a lot, for several reason. One is that the putting the animals up for sale is rather time consuming, another is that some players don't like CC farming (buying animals, reselling them).
It is not designed to be a community experience. If it was there'd be ways to interact with other people and their zoos. The point of franchise is to have your own franchise with your own multiple connected zoos. This is a single player game with the very limited "multiplayer" feature of being able to buy animals from others. It is not the only way to get animals as frontier refreshes the market very often with animals. It is a benefit overall cause you can get higher quality animals as well as albinos if you like.
Basically my point is this idea of "community" within the game itself is a facade that people need to let go of. The actual community is out of game in forums and workshop.