It's less a case of "boring" than of "It ain't broke so why fix it?" (even when there is a need for "fixing it", or at least a good reason for considering alternatives). One good look at what the British and Europeans are (and have been) doing in this area is proof enough that the prejudices against using EMUs and DMUs here in the U.S. are pure crap, but that won't stop the "true believers" from whining...