I think this thread's premise is misreading secularism speech a little, so I'd like to attempt to reframe the issue. To start with a bit of context, I'm agnostic (father agnostic, mother undefined spiritual, also real reverent of Jesus), progressive, and am generally careful not to say hurtful things to people.
So, racial epithets, misogynistic speech, homophobic slurs all attack groups of people, right? They're all derogatory and said with either hate or disregard and serve to other that group of people into a preconception of what all/most members of that demographic are. A lot of these are essentialist and dictate that because a person is of a certain race they are and will always be a certain way because of their race, sex, sexuality, etc.
I don't see people using 'god' in casual speech as attacking Christian religion or the religious so much as not (necessarily) participating in it. When people use these terms or phrases they don't seem particularly incensed, at least not at Biblical figures or practicing Christians. I think it's more that Christian religion has been ubiquitous in English-speaking countries for hundreds and hundreds of the years to the point where it has become intertwined with the language. Words like 'charity' even still possess their Christian connotation. I remember consciously trying to stop saying Christian phrases when I was younger and agnostic, but giving up because they're part of the modern American vernacular and I liked writing and expressing myself too much to give them up.
Back to the topic at hand, when the Allies curse or invoke the almighty in streams I don't think it's about god at all. It's not that they're profaning, it's just that they're not participating. Conversely they could just be faithful in a different, perhaps less detail-oriented way.
I really do think that the 'direction' of the offensive speech is imperative here. 'God,' besides its religious connotations, is an English word with a general meaning not necessarily specific to any group of people. Slurs like the one PewDiePie used are very targeted. That specific slang became closely associated with white supremacy and was used as a tool to enslave, subjugate, de-humanize, and oppress an entire group of people.
So I don't think comparing the two is intellectually honest (That's not to say I'm accusing you of intentionally being dishonest, I just want to present another way of looking at things.) I don't expect this to help much at all, but I would suggest that the Allies aren't using holy nouns or curses in the contest of Christianity or worship. And I definitely don't think they mean to be hurtful.
Of course you're entitled to express your opinion and I don't assume to know how the Allies would respond to this thread, I just wanted to offer my interpretation. And with that I'll end my longwinded wall of a reply... wow that's a lot of pronouns!