The planet / Mother Earth is just a way to talk about connected ecosystems of this big rock we live on. Yes the rock is not alive, but life is important, even if your only concern is as a proxy for our own support systems. How much value you place on different lives - your own, other people, whales, monkeys, deer, bugs… you are free to value them differently, but I’d hope you would not gleefully accept that we should just tolerate the wholesale destruction of habits on earth simply because it does not appear to affect human survival on the surface.
In case you have not noticed, we are currently in the sixth great extinction of this planet, which is driven by human activity. I consider it beyond tragic and existential to know that many of the wonders of this planet are going away and never coming back. Humans can live with air conditioning or under ground, but that doesn’t help other animals. You can still view this under a human lens if you wish, but for many of us, those other kinds of life are worth something, and bundling up that value by saying “we must protect the Earth” seems quite natural and defendable to me.