Do you think Nasa are putting a lot at stake abandoning the Shuttle program and taking such risks as this disaster?
No. I think any country has the right to go to space. NASA has had accidents as well, including deaths. That's all this was, an accident (as of now, anyway). They have lost shuttles with a whole crew on board, more than once, I think. Luckily no one was on board. It will take time to get into the swing of 'running', for lack of better words, the space program, like NASA seemed to have done.
I think we can learn a lot from space about our planet and the universe and think abandoning it is stupid. Science helps people. Space things can help people. Say a meteor crashed an contained things that could actually heal people. Not unlikely, we don't know what's in space. Being in space could lead to first contact with aliens. Being in space helps us understand how we got here, what's happening around us, is something coming to crash into Earth? Where and so on. It's more that just a trip to space, it's helping us from being squashed from a meteor.