No, it's called basic maintenance. If you like you fish to be alive and disease-resistant, regular water changes are a must. If you don't mind watching them grow weak and sensitive and eventually dying, then don't change your water. It's a great way to kill fish.
I believe most of us here change between 30 to 50% of the water in most of our tanks every week.
I believe most of us here change between 30 to 50% of the water in most of our tanks every week.