When I see thru-hikers on the Trail they all seem to be wearing synthetic T-shirts. I, too, have them (I drank the Kool-Aid) but they stink something god-awful and wear out so easily.

Why don't modern-day hikers wear wool any more? (e.g., (http://www.rei.com/product/785073/.) Merino wool shirts are soft, comfortable in a wide range of temperatures, insulate even when wet, don't hold odors, and come in a variety of thicknesses.

Before I go out and buy wool T's for next year's thru, can someone tell me why most hikers seem to have switched to synthetic materials?