If you're concerned about what a "reasonable person" looks at, then you might want to look at how political conservatives in general, and Trump supporters especially, prioritize things. Trump campaigned first on banning all Muslims from entering the country, later suggested that we register all Muslims the way the Nazis registered all Jews, then after elected, he focused on a selective ban of immigrants from certain Muslim countries. He also doesn't want to admit any refugees from war torn countries like Syria, claiming that they pose a significant terrorist risk. Islamic terrorists kill at most about 100 people a year in this country. Yet recent polls show that republican voters place terrorism as the single most important issue in America today.
And Trump's rationale for building a wall which will cost tens of billions in tax payer money by any reasonable estimate - we are constantly told that illegal immigrants are responsible for terrible crimes in this country even though it appears that they commit violent crimes at no greater rate than citizens. Don't even bother making economic arguments against illegal immigration because if these arguments stood up on their own, there'd be no need to fear monger over crime and terrorism, would there?
The fact is, conservatives consistently prioritize any problems they think are caused by people who are either a) non-white, or b) non-Christian, and accordingly they are very easily manipulated by shysters like Trump.
If you think liberals are being irrational in putting too much emphasis on the impact of mass shootings, you might want to look at cleaning up your own backyard first because there are some very serious problems there. At least the liberals who are passionate about gun control aren't focusing only on targeting certain disfavored sub-groups. They may be misguided in their reasoning and cost-benefit analysis, but at least they aren't being hateful pieces of crap.