Your statement is absurd. The vast majority of those with children and pets do not damage rental property. Come on.
Dogs track mud into and stink up cars. I once lived with a dog that liked to drink seawater when taken to the beach and would have diarrhea 15 minutes later like clockwork. The first time the owner took him home from the beach in his leased car, he was in for a big surprise.
Also, juice is basically just soda. All sugar with very little redeeming value.
You'd also have to diaper kids for years after you'd normally consider them potty trained. Small ones don't plan ahead, don't tell you in advance, and aren't as determined to hold it as you might be.
You'd also need to have something to clean dirty hands.
My car is nasty. The seats are brown with aftermarket goo. This is how it is when you must cooperate and compromise with other people.
Not to mention that avoiding trash hardly seems like "a strong argument for a second car."