Question about Humanity from a newbie: Could a Morally Reprehensible Vampire have High Humanity?

I'm struggling to understand this issue with humanity loss.

So, given what I understand, Humanity is a Vampire's connection to their human life, and they lose it through stains which they earn by giving into the Beast. So far, so understandable. But what I'm trying to understand that it's usually portrayed as a high humanity character is fundamentally a decent person, when I don't actually see a necessity for morality.

The Beast, from what I understand, is a Vampire's primal, monstrous core. It's hunger, the monster inside that just goes "drink blood, eat flesh, kill, survive, listen to your monstrous instincts, focus only on self preservation" that sort of thing. But the difference between a person's primal, animalistic urges, and a person's morals seems less relevant to me.

Say we have a schemy CEO type character who does drugs, hookers, embezzles, fires people for no reason, total asshole: Say he gets embraced. Would he necessarily have a lower Humanity score than others if that's just who is is as a person? And moreover, let's say this guy has a hard line on the Vampire related stuff, he only drinks blood when he has to, never kills, he refuses to get in touch with the beast, because while he's a scumbag, he refuses to let himself be an animal. How's his humanity score looking?

In other words, if a guy is a bad PERSON, but refuses to embrace being a literal MONSTER, does that actually affect his Humanity score as he's still very in touch with his human side, even if his human side is shitty?