It is only being used to media being so dominated by one side of American politics which makes most of those seem unusually divisive. Many Americans hold the view that abortion is murder, and/or the view that keeping 2A is worth the cost for instance, it is just that mainstream media will almost always present these as being the 'wrong' opinion.
I think we have to qualify statements like "many Americans". Is it 1%, 5%? It seems the best stats I could find say that only 10% believe it's morally wrong in all cases, which is what I would consider equivalent to "murder". So a small minority, and even then, I'm not sure that 10% would characterize it as murder.
But Kirk didn't just stop at murder, he likened it to the Holocaust - that is a far more inflammatory and sinister way to frame something. Again, he wasn't looking for nuance, he was looking to stir the base, trigger reactions, and promote his brand. I would also say that Fox News is as mainstream media as it gets and it certainly doesn't mark this (anti-abortion) as the "wrong opinion".
Do you think we live in a perfect society where we can have armed citizenry and not have a single gun death?
See now that's a very sensible way to frame an argument. If we want to have guns for protection against the government or otherwise, that comes with certain costs, and we need to evaluate tradeoffs and address problems.
That's not the nuanced perspective Kirk was taking. In the aftermath of a mass shooting, possibly the most fraught time, he flat out just said that we should just accept mass shootings, where in reality a big part of the reason for their occurrence is extremely lax gun laws and powerful lobby groups.
Charlie would be the kind of guy to parrot talking points about how it's a mental health or radicalization issue, but at the end of the day, it's far too easy for weapons capable of doing extreme amount of damage very quickly to end up in the wrong hands.
The audience Kirk was able to attract were probably some of the most vulnerable folks in the US. Just like Nick Fuentes can get a cult following from disenfranchised men, Charlie was just the next step up, using religious dogma and inflammatory language to take advantage of people's fears and propensity for tribalism.
Religion in particular is a powerful tool to keep people in line, it's administered to folks at an early age, when their parent's love for them is contingent in adopting religious views, which is why breaking away from religious dogma and trying to think critically about such topics triggers a survival response.
The irony is that Dems/Reps don't see themselves as falling prey to groupthink and belonging to some cult. In both the Floyd and Kirk cases, their respective "sides" lionized them despite them being overall reprehensible people, while the other sides making light or even celebrating the event, rather than having a common sense discussion about the actual problems, and trying to bring down the temperature.