I disagree. It seems to me completely rational to say "Guys, why are we doing X? It looks like there was a reason why we were doing X before but the reason is irrelevant by now and we still keep doing it. Since I see no reason to keep doing it, I suspect it is pure inertia and we should stop doing it. If there is a reason I missed, please point it out".

It's rational to say that about a topic that you don't understand. It's no sin to not put significant time into understanding every topic one wants to speak about and asking other people for insights.

Imagine you start working in a software company, and you discover the codebase is a jumble of spaghetti. You say "what is going on here? why don't we remove all of this legacy code?" and the other person goes "this is a arguing from ignorance, the fact you don't know why we need this code doesn't mean there is no reason!".

If you start working at a company you are ignorant about why the company is acting the way it is. If you are starting at a company you haven't put significant time into understand it's inner workings.

You didn't focus on asking a question. Your posts doesn't contain any question marks expect in the part about polyamous marriage.

There a huge difference between: "I don't know why we do X, we shouldn't do it." and "Can you please explain to me why we do X?"