I don't think this is arrogance, no one is lacking in humility and skepticism. It is more a matter that any and every claim need not be treated with the same so

I don't think this is arrogance, no one is lacking in humility and skepticism. It is more a matter that any and every claim need not be treated with the same sort of gravity as a rigorously investigated subject. The scientists in question are most likely dismissive of people purposefully ignoring evidence that does not fit into their world/political views rather than view points rooted in scientific data. It is absolutely important to care what others' think when it comes to topics in science. We live in a society, and others' views and ideas unfortunately will most likely impact people other than themselves. People are free to be as ignorant as they want in isolation, but the moment they start affecting policy, we should care.