Yeah, I don't understand that. I don't mind it either.. but they need to be consistent. Real people don't switch like that, even under stress.
No, actually they do.
While not universal, a lot of people actually do to become much more religious when they're in mortal peril, dying (or think they're dying), or are approaching old age (and thus their own mortality).
While not universal, it's pretty common for born-again Christians or recently more annoyingly religious folks to cite a "miracle" or "life-changing experience" (usually a near-death experience or a fatal diagnosis) as the imposes for their renewed faith / devotion in God.
While not universal, a lot of people who find themselves in near-death experiences (a robber pointing a loaded gun to their face, falling down a well, getting lost in the woods, etc), suddenly they start praying to God more fervently than they ever did in their lives, hoping against hope He (or some other higher power) is up there and hearing their prayers and doing something to help them.
People are terrified of death and the unknown fate thereafter, so it's much more comforting to think there's a higher power that'll protect and look after them. Aldous Huxley discusses this in his dystopian future books. Notice that young people (on average) tend not to be very religious because, as the saying goes, "Young people think they'll live forever / have their whole lives ahead of them." By contrast, older people (on average) tend to be much more religious. The difference? Their death is coming, and suddenly they wanna get in on the good graves of that higher power that'll protect and shelter and preserve them after death.
Again, I'm not saying it's universal, but it's not non-existent either.
It would shape your whole psychology if you believed you were on your own, more or less.
Except they don't think they're on their own. Not completely. They believe that there is a Maker's out there, and that faithful souls "go to the Maker's side" when they die, and that the Maker will come back and look over mortals again if they suck up to him longly and widely enough.
While religious dogma says, "He won't come back till that day," the terror of their own morality and the basic primal need that all humans have for a loving, parental figure to protect us when we're scared and/or in danger would believably push them to move "until that day" to "today is that day."
Besides, notice they name you the "Herald of Andraste," not "the Herald of the Maker." The Maker may be described as a full-blown misanthrope, but Andraste hasn't been.
The Jury's still out on where her followers think her soul went after she died (I mean, besides "The Maker's side"), but no one said she hated mortals and abandoned them too. As Leliana and Cassandra tell you at the start of the game, people were desperately terrified when the sky blew open and demons poured out, then a random person stepped out of a rift with a mysterious woman seen behind them. Later, that person was discovered to have the only means to closing the hole in the sky and saving everyone from becoming demon chow. People wanted to believe, "That woman was Andraste! She's come back!" because then it means divinity is on their side. A higher power is looking out for them.
The Maker may have abandoned them, but Andraste hasn't. And technically the Maker loves Andraste (she is his "bride," after all), so if she gives her personal seal of approval to the Herald, then the Maker might begrudgingly help out too.
Mostly though, I think they just tried to play with this "intervention" angle because someone in charge thought it was an "awesome" idea, and everyone simply had to go along with it.
That's fair. I agree.