Well as a religionist, I’ll do my best to accommodate you.
Now I know you’ve stated you have no wish for definitions of faith, but for the sake of what religion must say on the matter, I might have to grind in a small one here. The reason for this being, is because “blind faith” is somewhat of a loaded term(though not that you intentionally loaded it), one of which I think most religious folk will stay away from. In a conversation with someone religious, they may end up using it, or, as I have seen before, they unwittingly grasp on it when it has been fed to them from the opposing side. But regardless, “blind faith” is loaded because of the fact that if you have a secularist and a religionist both using it within an argument, they usually both have different ideas of what the phrase is actually representing…which generally never ends well.
For someone religious, they consider “faith”, or even sometimes, “blind faith”, as not easily letting go of knowledge which you have been given by God. I think there is a small example I can give to give a bit more illumination of why Christians, and religious people in general, consider faith such a big deal. Not only does this example help explain faith, I think it gives an easier understanding of the religious, and moreso for myself, Christian, faith on the whole. Now, as I’m sure some will be all to eager to point out, this illustration is a bit childish; but being so, it conjointly is very telling for those who can’t make heads or tails of religious nutjobs. The example of which I am speaking, is simply viewing the story of Horton Hears a Who, in Christian terms. Now as we all know, Horton, some random elephant, hears a small person inside of a flower, and go around telling people about it. And as we all know, no one believes him; but he knows what he heard. You could have had lined up all the animals in that story and have them tell Horton one by one that he’s crazy, but he would have, as he did, not relent in continuing belief that he was right. Those same animals could have shown him all sorts of evidence, such as the fact that no such people have ever been seen or heard before, and no other flowers seem to hold any “tiny people” inside them, yet he still wouldn’t relent. And so too is it for the religious. Now I understand its a silly comparison, but it very much does provide an equivalent story for what we believe–that a spiritual being has made itself known to you, and has impacted you in a significant way, and allowed you to understand the world, and yourself, in a way you may never have otherwise. The same effect that made Horton try to flee with the flower and grip it as tightly as he could before he would allow it to be burned, is the same effect that impacted thousands of those who would absolutely not recant their faith in the face of imminent torture and execution.
On the flipside, however, when a secularist perceives the idea of blind faith, they, usually reasonably so, consider the phrase in the terms of some construction worker who built a house, and after doing no tests whatsoever, and having consulted no manuals, decides his house is soundly built. Its easy, and by all means, sometimes blatantly necessary, to label religious thinking as equivalent to my little builder here, but isn’t taking into consideration the thought process that those who profess these things actually go through. As is unfortunately, in my experience, the case all to often, secularists generally end up at the usual places…the Crusades…or the inquisition…or 9/11. They generally don’t think about what these things truly meant to those who allowed themselves to have a steamroller crush them to death, or the nearly destitute single mother of three who had faith that somehow God will provide food for her children, and she happens to find food in her fridge the day of. (And to parachute in and cut you off at the pass…no…I’m not saying angels went to the grocery store.)
Faith, as Paul defined it, is:
Now faith is confidence in what we hope for and assurance about what we do not see.
Hebrews 11:1
What is good about faith, or if you so desire, “blind” faith, is that it creates an air of total trust between creator and created. To live in a world such as ours, there is plenty to fear and be afraid of, or even simply unsure of. To seek after and cherish such a trait is stated as a noble thing, because it supplants the feeling that “I” am going to handle myself, and “I” am going to provide for myself. Ours is an existence of “I”, by simple fact of how we interact with said existence, and so removing that from the equation is an extremely difficult concept for us, which is why we religious types hold faith as such an important value.
…of course, most of this doesn’t jive with your own world view, which is perfectly understandable, but I hope at least you’ll see a bit better why we put value in the idea.