I will clap for this simply for the mention of the “Do They Know It’s Christmas” video (remember when it came out)

In all seriousness, I think much of what you say at the beginning of the post is grounded in what is known as The Establishment Clause of the First Amendment to the Constitution:

“ Congress shall make no law respecting an establishment of religion”

It has been held by SCOTUS to mean that no governmental entity should respect an establishment of religion” which is why we have had all the grandstanding nonsense by politicians like Judge Roy Moore about the 10 Commandments etc.

What religious conservatives seem to forget in all of their outrage about the difference between “holidays” and “Christmas” is that the establishment clause protects all religions from being enforced out of existence by any one dominant and politically recognized sect.

For instance, lets say in 40 years given demographic pressures the United States were to become dominated by a different religion, in a country where Government could establish religion, Christianity could be at threat as politicians of this or that religion were elected and could use government funds to help protect their sect or faith.

In addition, as you noted, the First Amendment also protects non-believers from being discriminated against or forced into religious observances in public spaces. This was a country founded on religious freedom (which certainly includes the right not to have faith in a religion).

I am a Christian but I am also a civil-libertarian and I believe the Constitution’s genius was in allowing Democratic decision-making while at the same time protecting us from the tyranny of the majority.