With all due respect, promiscuous anal sex is a lot different than not washing your hands. So too are the consequences of the behavior, or failure to act.
If you cannot see a moral distinction between the two situations, I cannot help you. It's sort of one of those, "you either get it or you don't."
Seems to me though, you are spending a lot of time in "self-righteous moral indignation" (I think that's the phrase you used) about folks who do see the difference between the two situations and are cheeky enough to say so. Your morality says that anyone who sees a moral dimension to sexual issues should shut up NOW. If they don't, Alter Kaker will scold them like Church Lady. See the irony?
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That sound you hear is me, applauding. Well done.