The problem with your analogy is either the people of the religion need to view it as botulism or the vast majority of society needs to view those people as botulism.
The people of the religion are at best going to see it as tobacco. I hate tobacco; smoking isn’t pleasurable, it just makes me feel sick. But there are people who love it. You and I may see their religion as devoid of anything good, but to them it’s good. They are often born into it and want their religion with the negatives you and I see. It has nothing to do with liberal Christians.
And it is not liberal Christians that make it so we don’t reach the threshold of the vast majority of society not tolerating the bad Christians. The bad Christians are a sizeable enough part of society on their own to guarantee that. And as a society, we’re fairly geographically sorted. So even if they were only 5% of the population, they’d still often be surrounded by like-minded individuals and be able to wield political power. Plus, they’re still people. Even the most evil people generally have some redeeming qualities.