I think Viking's got it.
If there's no proof something exists, no solid inference it could, and no way to explore the possibility beyond a thought exercise, what's the point in believing in it? Personally I find there's plenty that I can look directly at and try to figure out, I don't need something I can't even see. Occasionally things which humans aren't even supposed to be capable of visualizing. Lots of 'intangibles' can be found and shown in patterns, or measured with things more precises than the basic human senses, but we haven't really found anything that actually makes sense to attribute to some force that we cannot possibly understand.
In fact every instance not specifically religious I can think of someone claiming we couldn't possibly understand, we now do to some extent or it's been exposed as a hoax.