This depends on your perspective. Native plants offer many benefits to our gardens besides the potential for lower maintenance. To me, the most compelling reason to grow natives is that they are part of our natural heritage and the ecology of a region. The local native-plant community makes the Midwest visually distinct from the East or South. Our gardens are habitats, and each plant contributes to the overall health of that ecological niche.
Plants provide food and cover for insects, which, in turn, are food for birds and mammals.
The purist, natives-only approach has merit, especially in restoring a specific plant community, such as a wetland. However, when humans alter an environment, it becomes more difficult to grow only regionally appropriate natives. A woodlot cleared for farming a century ago, and subdivided for housing a decade ago, has changed considerably. The forest that once grew in rich, stable, humus soil has vanished. Crops and erosion have depleted the soil, and construction has compacted it.