If I understand you correctly, you're saying...

Yes, that's pretty much correct, except for one very important thing.

You didn't actually say it, but there's a subtle implication in the way you framed my position that the causality runs in a particular direction, i.e. rationalists strive to discipline their thinking etc. and AS A RESULT lack awareness of an entire field of human experience. That is wrong. In fact, it's exactly backwards. (And I can now understand why you might have found it offensive.)

The causality runs in the opposite direction: some people lack (first-hand) awareness of this important field of human experience, and because they lack this awareness they tend to become rationalists. So this "lack of first-hand awareness" is not necessarily a deficit.

Here's an analogy: some people feel addictive cravings more than others. Someone who doesn't experience addictive cravings might have a hard time empathizing with someone who does because they can't imagine what it's like to have an addictive craving, never having had one of their own. So they might imagine that kicking an addiction is a simple matter of "exercising more self control" or some such thing, and have a hard time understanding why an addict would have such a hard time doing that. In an exactly analogous manner, someone who is not sensitive to spiritual experience might have a hard time understanding or empathizing with someone who does. It does not follow that not feeling addictive cravings is a bad thing.

Rationalists are the last group of people I'd expect to miss something so crucial, if it were real.

That depends a great deal on who you consider "rationalists." I've met a lot of self-identified rationalists but who are not even willing to consider the idea that spiritual experience varies across the human population as a hypothesis worthy of consideration. Heck, this article got so many downvotes early on that it almost cost me my posting privileges here on LW! Harshing on religious people seems to play a very important role in the social cohesion of many groups of people who self-identify as rationalists, and so it's not too surprising that the suggestion that there might be something wrong with that is met with a great deal of hostility. Even self-identified rationalists are still human.