Our ancestors had access to less evidence and experience than we do, and all too often what seemed a good idea at that time, gets in the way now. Appeal to tradition is used as a curiosity-stopper - usually when the idea can't defend itself against progress on its own accord.

I agree with this bit. But being an old tradition isn't evidence against a custom (even if most of the customs we should discard are old traditions). There are loads of old customs we don't question, simply because they're obviously true (like agreeing to use language to communicate).