"How many" =/= "all." I know plenty -- plenty -- of people who are gracious, knowledgeable, open, tolerant, and welcoming where religion -- and non-religion -- are concerned. You're acting as if "religious family" = "intolerant, overbearing, narrow-minded a-holes." Sometimes it does. Sometimes it doesn't.
Actually, I'm acting as if religious upbringing covers a spectrum, and that the negative end of that spectrum is more significant than suggested by your descriptions of a religious upbringing.
Sometimes people get killed in cars. Shall we ban all cars, even though not all cars = death?
"The vast majority of drunk drivers don't hit anyone. Should we ban drunk driving over the actions of a few?"
One can be religious, rear one's child in one's religion, and still offer that child a choice.
Lots of things CAN happen. Children CAN be brought up in wonderful or horrible environments - religious or irreligious. On this issue, I'm more interested in the overall trend: on average, do you think that a religious upbringing helps or hurts a child's ability to choose a path for themselves later in life? Do you think it helps or hurts the child's intellectual and emotional well-being? I say it hurts more often than it helps.
We hear much more often about the harm of a religious upbringing than the harm of an irreligious one. When metis touched on the negative consequences of his cousin being raised without religion, the "harm" he described was the fact that his cousin wasn't as informed about religion as he might not have been... IOW, the sort of "harm" that's unavoidable in parenting: no parent knows everything or does everything, so there will always be areas where the child will end up having to go elsewhere to fill the gap between what the child wants to know and what the parents were able to teach.
OTOH, when we look at the sort of harm that can be done by religious upbringing, we often see serious psychological harm:
Religious Trauma Syndrome
Even relatively mainstream religions can have nasty, long-lasting consequences. I've never heard of anyone dealing with decades of nightmares and phobias from being raised
without religion. I hear about it frequently from people who were raised religiously... and not in wacky fringe groups or cults, but normal, mainstream denominations.