Could easily be based on safety or accountability, rather than equipment durability. If you yourself have the responsibility to load the magazines with the right number of the right type of ammo you can't really blame someone else for doing it wrong. Probably. And there are for sure examples when there's really some facts behind it, but lack of understanding has led to these facts being interpreted incorrectly. The myth about the coolant moving too fast to cool the engine when running without a thermostat is a good one. Sure, the coolant will move faster, but the most important difference is that you lost a restriction at the outlet from the engine, leading to lower coolant pressure inside the engine. Lower pressure means lower boiling point, if you were close before now you may get boiling coolant at hotspots around exhaust ports and combustion chambers. Then you have steam bubbles reducing contact between coolant and metal, making it all worse so it boils more... So sure, removing the thermostat will make the coolant move faster, but it's the loss of pressure that can bring the engine into thermal runaway IF IT WAS BORDERLINE BEFORE. If it had a good margin from boiling before it'll probably run cooler without the thermostat, so these results that are the opposite of each other probably confuses a lot of people. They collect the limited facts they can, try to figure out how it all fits together... and manage to hammer the puzzle pieces together in the wrong configuration.