The difference being that an object's "mass" has very broad implications for all the theories that incorporate the notion of an object's "mass", all of which have been tested to high precision. (In tests that range from being contrived to not at all.) You can't say this for "intelligence" in anywhere close to the same way.
But it seems more HNers are dead set on believing that there is a genetic factor that can make certain people more "superior" than others, to justify existing social hierarchy.
Does it also bother you that tall people are statistically more successful basketball players? Or that wiry people are statistically better marathon runners? If no, then why does it bother you that intelligent people are statistically more successful in positions that require complex mental work?
The intelligence trait is real, not imaginary. Sure, it's a lot more complex than a simple, well-defined concept like mass. But then again, that applies to everything related to the human mind.
> [...] to justify existing social hierarchy.
What a weird attitude... Would you prefer that someone's position in the social hierarchy is even more strongly determined by their parents position or money? As was the case in medieval Europe?
But it seems more HNers are dead set on believing that there is a genetic factor that can make certain people more "superior" than others, to justify existing social hierarchy.