Your anecdote does not qualify your statement.
The question is which is harder to fight against.
The part of your statement with which I disagreed

was the 'makes no difference'. If I have to choose between an adverse wind (as we all know, if the wind is not apparently adverse then there is no wind at all) or a hill-climb then there is a difference because long experience has taught me that ceteris paribus, I can leave the whippets behind

when the resistance is simply a headwind, irrespective of their tri-bars and stuff and the fact that they left me trailing up the hills. It's good for morale

So yes, I choose a headwind over hills if it is simply a matter of performance.
The other problem with hills out here is that very often the sun is shining

on the slope up which I struggle and the heat can be oppressive. A headwind is usually a cooling influence

.