General Aviation is dying, unless something changes it will dissappear completely. This may assist in reversing the trend, much as the commercial lobby may not like it. Unfortunately FAA has nannied the GA field into the ground, planes are too expensive to certify so the field is dominated by expensive dinsaurs, the average ages of GA planes is so old that if it were alive it would have flaps of loose skin and wrinkes.
In short this is about user choice, be clear about the risks, let people provide reviews of the pilots skills and get on with it.
I don't really think that the 15% margin is justified, 1% should cover costs here and another 4% for lobby expenses, the rest is greed.
As far as the commercial pilots saying this will fail,
1 You have a professional bias, get over it
2 FAA is under pressure to ensure that GA doesn't fail
3 If this is demonstrably "non-commercial" it should succeed