...Because the curse trapped everyone in Storybrooke? They literally couldn't leave. Bae wasn't in Storybrooke, so 金牌 wanted it broken so he could leave and find Bae.
I think it's because he can't leave town without losing his memories. (I haven't seen the 秒 half of season two yet, so this may be inaccurate, but based off of what I've seen this seems like a plausible answer).
