There's a little more to designing and building a helicopter that won't kill you, than there is to an RV or similar.
Vans also didn't design their own avionics, nor engine.
Many amateur builders have also left holes in the ground, that might just come with the territory when cost is a primary driver.
Regions also have different rules on amateur builds, particularly when it comes out of a production facility so it will be interesting to see how this 51% self-build is viewed so it doesn't become a short-cut around certification.
The proof will be in the pudding, and until something leaps off paper and into the air it's all academic.