To me it's not just the "under God" part, it's the fact that my kids (or I) have to pledge allegiance to a country at all, because how it intertwines with the government. It's not much different than pledging allegiance to kings back in the day (and comes from that).

I don't see what I should owe any country my "allegiance". If you interpret "the country" as being "the people in this country", then yes, I feel a responsibility towards their wellbeing, and I accept that as a form of allegiance. But in practice "the country" isn't really interpreted as "the people" but rather "the government", and is highly exclusive (us vs them). And if a government is largely contrary to my values, and isn't (in my view) helping me or the people of this country, then why should I owe it any particular allegiance? Allegiance shouldn't be automatic, but rather earned. And the recitation of the pledge in schools is part of trying to make it automatic.