In my opinion, Tachain is a great project and it can be a pioneer in combining advertising and transport. With the discussion about the money-back guarantee, you get the impression that the project has already failed. I'm still optimistic that Tachain will be successful.
You dont outrightly say a project had failed. There be no guarantee of profits anywhere, but here we find one. I think we have left the basis of this project and are looking at an investor protection part of the project. Its a transportation and advert project. Take a look at the white paper and get the concept.
I fail to see how the project has failed when all they are trying to do is sell their idea to investors and if the investors change their mind in the future, they can request for a refund of their funds back.