Why, sure. Taken to that extreme it certainly would be.
But that's just it. It's just as "extreme" to a non-religious parent when their child becomes religious as when a religious parent sees their child become non-religious. You're watching someone you raised adopt positions you find abhorrent. The psychological and sociological processes are all still there.
All the same, the general trend is still there and appears to be well supported by the data and directly observable facts.
Sorry, which general trend?
I'm well aware.
It doesn't really make that extreme a difference, though.
How do you know, if we don't look at actual data? How in the world would it not make a difference to the worldview a child ends up with to have atheistic or even anti-theistic parents? You really believe that exerts no influence?
Sorry, but that is just not true. We just have to take a hard look around. Or even collect some anedoctal data, in this particular stance.
You don't think there's even anecdotal evidence of children raised in irreligious households knowing that their parents would react poorly if they became religious?
That is actually not the proper question to ask, and not just because there is so little ability to even define what would count as a non-religious person.
It would be done the same way it's done in most all studies of these groups: by self-identification.
There is also the much greater matter of how much acceptance of variation of belief stance (not "religiosity", which is a whole different kind of thing) is typical or even legally possible in various communities.
Whether there is some hypothetical "acceptance" of variation of belief in a household isn't the question we're asking, though. You said: "True... but it is not like secularists consistently have only - or even mostly - secularist offspring."
That is the statement I was responding to and hoping to evaluate. The question is very simply: do irreligious parents raise mostly irreligious kids?
The answers are apparently both fairly clear and incredibly taboo. Also rather unsurprising, once you take into account how assymetrical the situations are in practice. It isn't really possible for even very "extreme" secularists to hide the existence of theists, even radical ones, among their communities.
I'm not even sure what we're talking about here.