DH is American (by birth) but also has British citizenship. We met, live and had our children in UK. No current plans to move to US.
Children are entitled to get US passports as well as UK ones. But my understanding is that at same time they are issued with a social security number too and being US citizens has implications for future tax situation. US citizens are taxed on worldwide income, regardless of where they live.
I feel this could be a huge burden to place on our children when they may never choose to live or work in US. DH places significant value on US citizenship for them.