If persons are identifying as X, how many are doing that because they know about the foundations of X and/or read and retain the information of the texts that define X.
Someone says “I’m vegan” but eats meat, are they a vegan simply because they say they are?
As for their being a “much smaller” LBGTQ population, as a percentage of population, back in the late 30’s through the end of the 20th century is bizarre. LBGTQ people existed in much the same numbers, they just hide because they didn’t want to risk arrest, imprisonment, lose of job, etc.
The idea that are somehow “more” LBGTQ people today because laws have stopped arresting them is a absurd.
Stonewall demonstrated, the exact inverse of what you are saying to be true.
I think it can be argued that most values in western culture predate christianity and are values Christianity adopted for Judaism or various “paganism”. (I put that in quotes merely as a inclusion of to many non-Judeo-Christian to list in reasonable manner. It is not meant as a detrimental notation.)
I actually think making characters as ambiguous as possible from a faith standpoint is the best model. If you say, OK, this character is of this particular faith, it makes that character harder to relate to if they are not of your faith. A kid can dream about having superpowers (pretending to be superhero-X), but, do we risk making characters less relatable by making their personal philosophies explicit. There are a hand full of characters that are of one theological bent or another. That’s great. It establishes that these alternate earths have similarities to our own. Those religions do exist, and some characters are explicitly of one particular faith.
I think it would be problematic to say Batman is (pick a given belief structure). How many people of various faiths relate to Batman, in part because they can see an idealized version of themselves in that character. So keeping some ambiguity in that area is actually good.
It’s good that we have a handful of LBGTQ characters and hopefully more in the future, because they have been a marginalized group, and specifically working at creating inclusion of that previously marginalized group is healthy. We saw this with an increase of heroes and villains of color in the late 60’s/early 70’s after then end of Jim Crowe in 1965.