Those arguments of school textbooks are an American thing.
As far as I understand it (not being American) it is a side effect of the Constitution. Particularly the bit that guarantees freedom of Religion by keeping religious expression out of state financed institutions. When the Constitution was written freedom from religious persecution experienced by many migrants from a Europe riven by religious wars was pretty high up on the todo list.
However, the religiosity is still a significant feature of the the culture of the US and it is sometimes politicised. The US has a Religious Right aligned to deeply Conservative values. Christianity is a proselytising religion and some groups would like to use state institutions to promote their interpretation of religious truth.
Hence the arguments about abortion, teaching creationism in state schools and religious symbols in public buildings.
Other countries sometimes have disputes like this, but the US, being such a large county, the cracks are a bit more obvious. Many European countries have had a long time to evolve constitutional solutions to the State v Religion issue.
The UK actually still has a few members of the upper house of Lords that are nominated by the state Religion, the Church of England. One day they will get around to dealing with these constitutional anachronisms but they are not a priority because religion and the monarchy no longer figure in arguments over who runs the country.
That is not the case in the US, where there a constant debate between political factions who exercise their power by associating with a point of view on a religious or cultural issue like school books or abortion or gun ownership. These are very American concerns that are really not an issue in other countries.
Other countries get themselves into a state arguing about quite different stuff that can be quite puzzling. I am pretty sure there is a lot scratching of heads over why the UK is so uptight over this Brexit nonsense. 