It's your WITHOUT A DOUBT WHATSOEVER dodge that gets in the way of clearing this up.
There are too many variables in any flight, let alone a combat flight with bullets flying and lives on the line, to identify one thing out of thousands of other variables as the sole reason for anything happening.
It's a red herring.
Let's try another tack: explain why ALL aircraft had manuals that instructed the pilot how to use the engine, and then explain why, if he could "just throw the throttle forward and not worry about it", the manual wouldn't just say that? Keep in mind that the folks that wrote those manuals knew full well that the pilots were going into harm's way with the planes. And, keep in mind we know that some "margin of safety" is built into those*.But we also know there's a big difference between 'minding a margin of safety' and ignoring the instructions altogether.
Finally, if it was all so automatic, why were there even any other engine controls other than throttle in the pits? Why were those "unnecessary" mixture, prop pitch, fuel mixture and cooler flap controls even THERE?
Also, to head off your next spurious argument, it is not within reason to expect the pilots of the sim/game aircraft to go to some lengths to preserve their aircraft for longevity, even if the game doesn't actually support a "real" career and a "real aircraft life"? Otherwise, where do such hypotheses stop? Do we then just say, "Well, let's say just for the sake of fun, that all planes had unlimited ammo and gas...you just don't need to worry about it. It'll be more fun, and I can rack up a 350-kill mission...[Beavis and Butthead style laughing ensues]"
*(Best example of that is a manual telling you not to spin the plane, and of course we all know that it can and will spin, given the right situation; idea is not to lose aircraft and pilots doing unnecessary stunts that are unsafe)