Their phrasing is a response to your something most don't agree with, this comment doesn't reply to their meaning.
What they mean is, historically, the majority has not always been correct when it comes to ethical issues. That's different than arguing that majorities have always been wrong.
Going to look back on modern factory farming (the source of the VAST majority of meat eaten in America) as something so abhorrent (Both for the process of it and the external costs) we’ll be embarrassed to tell our grandkids about it. Although as I’ve been downvoted for saying here before, if you’re having kids and grandkids, you’ve already done uncorrectable damage to the environment so go ahead and eat meat or whatever. Doesn’t matter at that point.
I hope (but doubt) that killing animals for food (whether by hunting or smaller-scale farming) will also become completely unacceptable outside of very specific situations.
So I Believe I understand where you are going with the kids comment. At some point as a species we need to procreate, so what method / system would you recommend?
If you’re alive today and care about doing something significant for the environment, don’t have a kid. That’s all there is to it.
There’s absolutely no shortage of people who a) will think this is bad advice that doesn’t apply to them because they are very smart, b) just don’t care, c) don’t have access to birth control, d) just really want a kid, etc.
What they mean is, historically, the majority has not always been correct when it comes to ethical issues. That's different than arguing that majorities have always been wrong.