No, I can't. I need to sell it on both markets to make it profitable. There's no way to have that large margins it could sell just in the US.
Not betting on your ability to come up with a new type of charging cable is not as big deal as you imagining it is. Maybe you should come up with a prototype before demanding all type of charging cables be allowed?
In fact, USB-C and magsafe are complementary. USB-C is commonly used by displays to provide docking station functionality, so I can buy any display and use it with any computer (instead of having to buy a proprietary docking station that is different for each model). If I'm travelling, I can enjoy the more robust magsafe connector but I can also use USB-C if needed.