What's the point of a rocket plane? Is the atmosphere getting too thin to support combustion?
Maybe they have higher goals in mind.
What was the point of Glen Curtis' first airplane, or for that matter Henry Ford's first car? They weren't the first, and they weren't really good for much.
The point is, there's money to be made lifting stuff into orbit. We're close to a breakthrough that will lower the cost per pound by 90% or so. Imagine a surplus B-52 carrier aircraft launching a rocket plane that's a quarter the weight of the shuttle orbiter but has the same cargo capacity. Suddenly space tourism is a reality, and missions to the planets just got 50% less expensive due to the lowered orbital launch costs.
I expect to see regular scheduled service to the International Space Station and possibly a couple of pricey zero-G resorts within my lifetime.