Because previously Bolton has confidently declared that Iran would never become a nuclear state. Now he has to be seen to say that Bushehr is not the isuue. The real issue is the uranium enrichment facilities. Iran having the ability to produce Plutonium as well as enriched Uranium is no big deal in the scheme of things. Don't worry Bolton is irrelevant ever since he couldn't get past the Senate to be the US UN ambassador onder Bush.
from the article: Ex-U.S. diplomat: Israel unlikely to strike Iran nuclear plant