The two words you need when making a justification is reliable and safe. It won't matter how innovative and energy efficient it is if it doesn't meet the above requirements. If the osprey taught as anything, flying unconventionally is hard.
I totally agree with you - getting this to beyond current single engine aircraft safety rates is going to be the challenge.
However, they've got a far better starting platform for doing this than anything else I've seen. It's made out of simple pieces with a lot of good options when things go wrong.
