Board Thread:Show-Related Questions and Answers/@comment-9186670-20171228010006/@comment-31231929-20171231061400

I think it's because there's a time-travel aspect to the curse in that the curse sent the characters back in time to 2017 (from around 2030) and they can't contact Storybrooke because the younger versions of themselves are still there would would create a time paradox.