Why should a person who goes to the park care about the park?

If people are dumping trash everywhere and all the plants and animals are dying, I assume you wouldn’t like to spend much time there anymore.

Sure another park might be opened, but constantly changing parks isn’t what you want to do long term. If someone buys up the basketball court and turns it into a cesspool of hate, you can unsubscribe from that court and remove it from your park. Adding another one that is nicer, without completely going to a new park.