To answer you in brief - calling anything that can't be shown with some level of accuracy to be true to be 'historically-based' would upset me. My irritation was that you stated (or at least, I understood you to have stated) that a Biblical game would be equivalent to a historical game, which is decidedly untrue.
In that case, let me clarify:
Not everyone likes history, but there is definitely a niche for historical games. Why not the areas of history covered by the bible?
Since a major part of the Bible is history,
It covers an entire rise and fall of a nation, from birth to destruction, to rebirth, to shortly before it's second destruction, it covers alot of ground, and intersects many famous empires in history (the Roman, Greek, and Persian, Babylonian, Assyrian empires, and the kingdoms of Syria, Egypt, Lebanon, and others).
and it is the single most debated and verified group of historical records we have,
Well, I certainly got the 'debated' part right.
I've already explained what I meant by 'verified' (poor word choice on my part!): That the bible hasn't changed (or only superficially) between what we hold in our hands today and what was written down thousands of years ago.
not to mention one of the most well-read and well-known portions of history, with people reading it across the most ethnic, cultural, and geographical boundaries
That with 2+ billion people having at least passingly heard some parts of it, and (wild guess) 500 million having read the bible, you have an audience that, despite being diverse in culture, may be inclined to play your game because they have read about those events.
If you made a game set during the Peloponnesian War, alot of people who've read about that time in history would get excited. A heck of a lot more people have read the bible than the Peloponnesian war, so it's a wider target audience.
I see no difference between setting a game in ancient Rome, ancient Judah (Israel), or ancient Babylon. We have little details of Babylon, slightly more of Judah, and alot more of Rome. Just because a game is set historically (to the best of our understandings of that region during that time period - which is in most cases, very little), that doesn't mean the game is claiming that the events portrayed in the game is historically accurate.
For example, my own game is set in a historic time period (around 1520s AD), but the entire game is fiction, and the location is fiction (a fictional colony of France). Because I'm not being historically accurate, I refer to my game as 'para-historical' (but not alt-history). This is to distinguish it from, say, a fantasy world setting. I'm saying, my fictional game is set in the real world, in a real time period in history, with no changes to real-life historic events, and that real-life historic events are referenced by the game (but, incase you were curious, it's not a game were you're going to actually bump into some specific person from history. I personally find those kind of scenarios too cheesy for my tastes).
Since I'm not being accurate to history, and am not trying to recreate or simulate history, I call mine para-historical (as in, 'existing alongside history' without conflicting with it). But if I was being historically accurate, and set my game in 1520s AD in France itself, I'd have no problem calling my game a 'historical' game even if the events were fictional (as long as they don't conflict with real events). I mean to imply by 'historical' that the game is set in the real-world historic world, not in middle earth.