Again, my experience differs. These were groups that got along fine, specifically until we realized that we had different ideas about alignment. Radically different, in fact. And I use "groups" for a reason. This wasn't a single group. Usually, two or three people would be of one opinion and two or three would be of another (occasionally you'd get another lone position but not all that often.)
This is why I say that it is not the idea of "be a good person," but rather the fact that different people can have actually different ideas about what that means. Sure, maybe 90% of the time they'll agree on what the good actions are in a given context, and what the evil actions are, etc. But even something as simple as "well, that's not an EVIL action, but it still makes you less Good for having done it" has, in fact, been quite controversial for groups I've played with.
Some people see it purely as a declaration: "this is what my character is, so what they do is that." No matter how much that may defy sense. Some see it as a purely descriptive pattern: "the sum of your actions up to now is this." Even though that conflicts directly with the idea of beings "made" of such a thing, or powers/forces directly comprised of the cosmic "stuff" of that alignment. Some see it as a "ball of wibbly-wobbly timey-wimey stuff," to appropriate a phrase, despite the other conflicts that causes. I've even known some who see it as literally universe-imposed team jerseys, with no moral component whatsoever, because (as they saw it) that was the only way to make it make sense.
And yes, this has meant that I now pretty much have to engage in a long, in-depth conversation with any prospective DM (and, ideally, the group at large) about how they think alignment works and what impact it has on the world. Because if I don't have that conversation, I get nasty surprises, more often than not. I get "I'm hoping for a world where heroism matters" cashing out as "the only heroes are those who die being heroic, but at least they accomplish something....for a little while. If they're smart and lucky." Now, I get that part of that is a "me" thing, as I love Paladins and especially playing a Paladin who hard-averts the "Lawful Stupid" archetype. But it sure as hell can't be all of it, because it's happened in games where I've played sorcerers and bards and tried to defy my natural LG tendencies.