Tesla monitors battery degradation based on miles driven. If you use your battery as a stationary power source, it messes up their ability to anticipate degradation. So it makes sense.
This is, from the warranty's point of view, the same as manipulating the odometer on an ICE car to make it appear to have driven fewer miles than it actually has.
This is, from the warranty's point of view, the same as manipulating the odometer on an ICE car to make it appear to have driven fewer miles than it actually has.