If it depends on the clouds, then in my opinion, a sunny morning is the most ideal color shown by the sky. But it turns out, on your images the weather is a little cloudy and that actually makes it an even stronger composition.
In my opinion, in the morning a lot of people are still sleeping, so the image will look pure nature photos without human activities. The rest is very rarely the morning image can be generated.
I do get what your saying and I agree that makes a lot of sense ;)