It's about the cow, religion, symbols, and societal norms. "Cow" we don't care about; "religion" we care slightly more about. But when it comes to the sanctity of symbols and conformity to the "right" social norms, DUers are all over it--as is pretty much everybody else.
There are anecdotes--some specific (1943, specific newspaper, in Turkmenistan) about an editor who was bullied until he was hospitalized from a heart attack and exiled from the Party (meaning he'd lose his job and any decent social status) for a typo: gavnokomanduyushchii, referring to a Red Army commander. "Glavnokomanduyushchii" means "commander in chief" or "supreme commander," but not necessarily Stalin. Drop out the 'l' and it's pronounced exactly the same in standard Russian as "govnokomanduiushii" or "shit-commander".
Fable has it that somebody else got 7 years in the camps in 1951 for the same typo.
Similar apocryphal stories about "polkovodets" (troop leader) and "palkovvodets" (stick-inserter) abound.
That these are apocryphal isn't the point; this kind story is plausible because of very real persecution for random errors that happened, not because anybody much cared about the person making the error, although that no doubt happened, but because such errors were jabs, however accidentally, at a symbol of state power and authority, a state with policies that many supported or a leader that many valued.
Couple that with suspicion and it's a toxic mix. Not about religion. Nor "what somebody's eating." Because we must protect and advance our symbols and our causes, our leaders and power that we support.