That is at least "inevitable" in groups that habitually mistake feelings for something objective.

People inevitably feel differently on given issues in any group. Blaming the other side for not really being objective/rational/etc happens no more in Objectivism than any other group.

Let me add that there is no inherent propensity in Objectivism to substitute one's feelings for objective evaluations; if that's what you think, you're misunderstanding something. For example, Ayn Rand had an entire branch of her philosophy talking about art, music, and "aesthetics" in general. Her opinion on music wasn't purely based on her trying to pass off her personal feelings for an objective judgment, but rather was indeed a derivative position of her philosophical system. And there's nothing wrong with trying to identify objectively best or optimal music or other things, that's actually perfectly fine to do in philosophy - but if you're going to use differences as a basis for building a community, you're going to produce a horrible mess with schisms and splinter groups galore, which unfortunately hit the Objectivist community pretty badly. Hence: "firewall optimal philosophy from optimal community"

Good grief, how can you do that when there is no agreement about what optimal means?

Well each person does it for themselves. Naturally the creators and leaders in the philosophy set the mainstream (er, sort of by definition)...