For the reader it should be made pretty obvious:
If the nebular hypothesis is replaced then their house of cards falls.
1. Nebular hypothesis goes, so does their theory of planet formation from gravity alone go.
2. When gravity isn't the dominate force that creates planets... we then have a serious problem. It means there is another type of force that is more important.
3. Establishment scientists heads and careers:
We first simply needed to replace the nebular hypothesis. Stellar metamorphosis does this: