It may well still be able to be dismantled by executive order. Just 1) the next President could put it together again, and 2) Obama doesn't have much interest in dismantling it in the first place.
In 2008 he campaigned against dragnet (or at least warrantless) surveillance. Obama's wikipedia entry says he taught constitutional law for twelve years or so.
Why is Obama not interested in dismantling dragnet surveillance? He also worked as a civil rights lawyer.
Obama has the education and experience to know that surveillance has lots of bad effects, and that some secret special reading of a law doesn't make it legal or ethical or constitutional. Why didn't Obama dismantle the universal-as-possible surveillance?
This is a really fair question. I think it is simply he doesn't want to look weak. The political problem with him fixing the EOs is he has to sign them. This is just a publicity stunt to blame someone else for not doing something he lacks the courage to do himself. Its truly mind-bending. A good leader would dix the stuff he can fix by himself and then work with other people to fix what needs to be fixed by consensus. POTUS is not that guy, tho.