I have only sold a few t-shirts but all of mine were changed from the default.
In fact, none of the pillows or totes were sold with the default setting. None of the phone cases were sold with defaults either.
I personally don't see anything wrong with the defaults they pick, but when I look at what people are actually selecting, they are colors or positions I would would not probably pick for those images. Because of that, I no longer mess with the settings on any of the consumer products.