Read this paper - http://www.faculty.virginia.edu/brod...0ME%202002.pdf you'll find that the most prevalent western genotype is concinnus (even accounting for snakes showing the phenotype of infernalis, fitchi, parietalis, etc). Simply, we are dealing with visual classification at best. As such the visual groups are always going to bring up a little controversy but the regional diversity is accepted as a list of subspecies and we do treat them as such.
It's why I prefer to see definate phenotypes in my collection and why I wouldn't want intergrades/questionably patterned snakes (I think the bill for gene mapping might be a bit steep ).