Considering that conservative has, to many people, a slightly different (and more often than not, negative) meaning than what the word actually means, the confusion is honestly a bit understandable. The word just has become tainted by its political connotation.
I don't know where it is from, but someone once told me that "Conservative does not mean to guard to ashes, it means to pass on the flame."
Sadly, to many people, it means the former - refusing to acknowledge or even actively trying to stop or revert progress, upholding obsolete, indefensible and deprecated traditions, values or positions and generally being unreasonable.
I would consider myself conservative in the true sense of the word: I want to preserve favorable conditions, a sustainable enviroment, an inhabitable planet and free and open knowledge and culture for future generations.
That's actually a really interesting characterization of conservatism. But, I can't help but think that when you phrase it like that, pretty much everyone would identify as conservative.
I guess that means that the problem is that unreasonable people on some level must believe that they're not being unreasonable. Worse still, now that you point this out, the bigger problem seems to be that, in addition to this, unreasonable people actually believe that it is the other people who are being unreasonable.
I think one contribution to the problem is the fact that in America it is not just acceptable, but encouraged to have strong opinions about things you don't understand. I generally am out of my depth in matters of climate change, the economy, and what to do about patents, and I readily admit it, rather than forcing an ill-thought out position on my compatriots. You never know who's listening, and I'd hate to look dumb in front of someone who really does know what's going on.
I can't help but wonder how many of these problems would be solved if such a position were adopted on a widespread basis.