Yes, also wonder about this. Spelt has no gluten in it and isn't considering wheat.
I guess the main reason are the lectins present in the husks of most types of grain. There's WGA in the husks of spelt (wheat germ agglutinin, you can google it), which is one of those things whose dangers haven't yet entered public consciousness. I once made the mistake of eating pure wheat germs--that felt bad.
And of course, it's carbs, but if it needs to be, I'd try white spelt flour.