Why do Young-Earth Creationists make such a big deal about the YEC view

For anyone who's unfamiliar with what the Young-Earth view, here's a starting point . I want to start out by saying that this question is not about whether or not the YEC view it true. It's not about whether there is scientific evidence for and/or against, or even neutral. This is in no way, shape, or form, a question about the validity of the YEC view, or any opposing view. Specifically, I'm asking why the Kent Hovinds, Ken Hams, and other prominent YEC creationists, and so many Fundamental conservative Christians so married to the YEC view, and so vocal about it. Most of the people that self-identify as Christians could care less about the issue. The idea of creation/evolution is a non-issue. Debating whether the Genesis account of creation and the flood has no bearing on doctrines they care about, from their perspective. As a matter of fact, many of them consider Creationists to be an embarrassment, and the idea of speaking out on the topic as counter-productive at best, and some think it's downright dangerous. They open themselves, and as a result, all of Christianity to ridicule because they "refuse to believe science" and stick to ancient stories. For the record (for the one or two people that don't already know it) I am one of those people. I'm a Young-Earth Creationist, so even though the above may sound like I'm attacking the YEC view, that's not why put all that in there. What I'm looking for is an answer as to why the "Creation Science Evangelists" - the Kent Hovinds, Ken Hams, the ICR, creationtoday.org, and others are willing to go around preaching something that gets them laughed at, ridiculed, and even other Christians wish they'd just knock it off. Why is it so important to them? Is there a doctrinal reason, or are they just that stuck in their ways that they're unwilling to change?