The point, as I understand it, is that even if these specific vehicles cannot be scaled up to have orbital capabilities (and I think they may well be), they WILL serve as stepping stones to vehicles that WILL have full orbital capabilities. With their suborbital "toys," these firms are building up the knowledge, skills, and technical infrastructure necessary for a real spacegoing capability.
Having multiple private space ventures is the best way for the US to stay in the space game. Why stay in the space game? Because the winners will be the dominant players in the planet's future. The more space-capable players we have, the better off we'll be.