They’re just bad Christians. Almost everyone who talks about “real Christians”—whether it be in an attempt to criticize bad Christians or an attempt to defend Christianity from being associated with its lunatic fringe—is engaging in the No True Scotsman fallacy. The only exception I can think of is Nietzsche, who famously declared that “there was only one Christian, and he died on the cross.” Then again, he was driving at a much different point in making that statement and wasn’t actually trying to divide “real Christians” from “fake Christians.”
It would be different if we wanted to use “Levitican” as a name for a kind of Christian. The author of the linked article briefly flirts with such a usage, but ultimately gives in to the fallacious division of Christians and Leviticans. If we wanted to be more careful than said author, however, then the term “Levitican” could be quite useful. It would be something to add to the list of terms identifying trends within Christianity and those who follow them. Leaving aside the various flaws of the linked article, then, I would say that “Levitican” is a good way of describing a certain kind of Christian.
@Nullo Voting against every legal barrier to gay marriage is being mean and abusive to gay people. It says that you think their legal rights should be circumscribed due to a (mis)perceived spiritual failing. It says that gay people deserve to endure more suffering and oppression than other equally sinful people who simply happen to be heterosexual.
As for the Biblical message on homosexuality, it is far less clear than you pretend. I have pointed this out to you before, though you chose to ignore it rather than make even the slightest attempt to defend your opinion. I suggest you spend some time meditating on Matthew 7:3–5. Maybe it can help you overcome your crippling bigotry.