I suspect all minds tend towards an emotive alarm when confronted by ideas other than their community’s home-grown ones, even if their community is an avant-garde and revolutionary one. Once you’ve formulated and settled on a theory, you are loathe to abandon it and start again, partly because your identity becomes bound up in it. New ideas are bewildering and necessarily imposed by outside forces. They are disempowering, threatening. Accepting them would mean betraying not only your way of understanding the world, but also betraying like-minded people.
An intolerant, thoughtless rebuttal that reaffirms tribal allegiance is much easier on the brain and on the sense of inner security. This is the essence of socially conservative, right-wing thought (as distinct from neo-con market-liberal capitalism.) It could also explain the furious reaction of reformers, rebels and disruptors to any challenges to their world-view.
Conservative mindsets are probably the silent majority in most communities (although all humans harbour more than one at a time, so this is difficult to assess.) Certainly, in Britain, we elect far more Conservative governments than progressive liberal ones.
However, it’s not just the conservatives. Everyone resists outside ideas, even if they are an improvement on the ones they already hold, or are more appropriate for modern times. Everyone is flawed and makes mistakes, harbours nonsensical assumptions and emotional responses they can’t explain. We need to be forgiving of ourselves so that we can accept this and be aware of our limitations, then actively school and correct ourselves. “To be swayed is the mark of a noble mind.” (The Iliad, Homer)