Where does it say that they can only be subject to some laws?Where does the 14th say they have to be subject to ALL our laws. The construction governs FEDERAL laws states govern state law. Regardless Indians live on land that the US owns and are subject to many Federal Laws. So why didn't the fourteen cover them . WHY did Congress have to pass an entire act to give them citizenship.
But let's assume that you are correct about only some laws. That leads to the following.
You are saying that Indians should have been covered under the 14th. You are making a strong argument for why it was wrong to not allow Indians to be citizens at birth. Because one group was denied their rights under the Constitution doesn't mean you can then deny another group their rights. The result of your argument is that you can't deny citizenship to the children of undocumented immigrants because undocumented immigrants are subject to some laws when in the US.