It’s the irreverence with which they are used. If the average European medieval peasant affirm their sincerity and honesty by saying “May God damn me to hell if I lie”, that’s an (implicit) oath. They’re putting their salvation on the line. That’s how serious the matter at hand is.

If I casually say “damn, that ass”, I’m using a boiled down version of that (when the oath formula becomes so widespread, people start omitting words because everyone knows what you mean anyway, even if you just say “God Damn me” and eventually just “damn”). But I’m not doing it out of a devout belief that the thing I’m saying warrants reinforcement by invoking divine wrath. I’m abusing the sanctity of good for an entirely profane matter. I’m reducing God’s power and wrarh to a colloquial tool.

Me, staring at my code, fiddling around, retrying it over and over: “WHY WON’T YOU WORK, DAMMIT?”

Me, late at night, trying to sleep, suddenly wide awake: “Oh that’s why!”

Me, the next morning, staring at my code: “…what was it again?”

I assume the “almost everything” is relative to the things people need to calculate gravity for. Astrophysics is cool, but rather the minority compared to, say, calculating the forces a bridge has to withstand or the arc of a ballistic projectile or any other calculations concerning primarily things on our planet.