I think you have hit the nail on the head. Since the Constitution provides no specific mechanism for determining whether a candidate meets Constitutional requirement, it by default is left up to the voters, the Electoral College and Congress.
Each has the duty to determine if a candidate is qualified. If no objections are raised by these bodies, I’m not sure I want a court stepping in and overriding them.
If we’re all so concerned about this issue, why isn’t anyone, to my knowledge, working for a policy that would prevent a future situation of this type?
All it would take is one state requiring all candidates present appropriate documentation before going on the ballot.
Several states are proposing statutory protocol that includes a requirement to produce evidence (e.g., show the birth certificate), rather than assert "qualified," for parties that aim to place a candidate's name on the ballot. That wouldn't cure the defect that I believe occurred in the recent election, because Obama openly acknowledges that he was a dual citizen at birth.
Plus, the current "policy" aims to prevent unqualified people from being elected. What to do if/when the elected representatives fail to be faithful to the policy? In other words, the issue isn't one of absence of policy, it's absence of principle on the part of the actors.