Scott wrote

Well, it seems to me the two things are completely
different. For a BIG decision, like going away, I
think it helps kids to see how you decide whether
they can or cannot do something. They'll get a
feel for those things that you think are important,
and how you evaluate options and come to make
decisions. They can also learn how to argue a
case. I think those are important skills to
learn. In your case, your child could have learned
about trusting 'gut' feelings over more tangible
arguments. Or they just could've learned about
'Because we're your parents and say so', which I
guess is what he learned here.

Not at all; I didn't give "because we said so" as the reason; I told
him the real reasons. To me, what you are suggesting sounds like a
mean game: let the kid argue his big case, even though there's no
chance he can win it. Why raise his hopes?

Seeing the decision
process ongoing is more valuable than talking about
it afterwards, IMO. That seems to be where we
differ.

I do think it's educational to know what factors went into a decision,
but I don't think it matters *when* the child learns what the factors
were --when the process is being decided or afterward. And any benefit
that might accrue would be outweighed, for me, by the added pain that
would have been inflicted on him by having to wait around biting his
fingernails, only to be disappointed.