I was actually born and raised a Hoosier, but am now a Texan by both accident of military service and choice. Texas has a fascinating history, and it is all relatively recent. I live pretty much in the center of where the Texas revolution happened, and it is pretty neat to be able to easily visit the key places.
As to why no consideration is given to splitting up into new states? There is no real compelling interest to take on a gargantuan effort like that, and it could very well have some downsides. Depending on how the lines were drawn, could very well end up with a new state that is hostile to our interests.