There was a few bad XT hubs a few years back but that was just a short term production problem. I doubt that the XT is so delicate that it can't be used for touring. It is a mountain bike hub, after all, and is designed for the rigors of mountain biking which are equal to or greater than touring or commuting. I also question the idea that LX is "from design to production...created only for heavy duty touring". The LX hub is a mountain bike hub as well. Bicycle people can be an opinionated lot with some odd opinions based on little evidence.

That said, much of Shimano's higher end line doesn't come in 36 hole hubs anymore. That may be the real reason that the wheel company won't build with XT. The best way of getting the wheels you want is to build your own. Or you could find a replacement rim for the Alex rim. If the rim has the same effective rim diameter (ERD), it's simple to loosen the spokes on the existing wheel and transfer the spokes to the other rim.