Yes, John
So, I guess the consensus so far (addressing the numbered parts above):
1. Every movie gets a pass for an unlikely introduction. After all, that is why the story is being told.
But
2. Unless we are attempting to tell a 100% authentic true story, all stories are made up, and thus, contrived. The only term we have is to refer to it in differing degrees: "feels contrived", "is a bit contrived", etc.
3. I could say a film has "too many small contrivances". An unlikely start followed by a series of unlikely events can break suspension of disbelief, though YMMV regarding what is a contrivance.
I'd really love to have catchier terms for this stuff, though. We have Spielberging and Baying. Would it make sense to say it was too much "De Palma"? Is there a writer or director I'm not thinking of who is known for contrivances or plot holes in what could be straight-forward or hard science movies?
Also, thank you for everyone's input. There have been plenty of good points about specific movies here. I'm just trying to stay on topic about the one thing that I can't well describe and puts me off plenty of movies.
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As a side note: I know not everyone feels the same as I do. But, just as motivations are supremely important in a drama, I feel fact is important in a survival movie. The danger in the plot isn't motivated by an antagonist. So, the survival situation becomes a kind of math: water, warmth, food, etc. The sloppier writer creates new obstacles one-by-one as the movie progresses while the better writer builds it all into the initial event. I'd love to give good and bad examples of this but my memory is crap.










