It's entirely possible that more "txtspk" words will eventually enter the language as accepted forms of conversation. That day has not yet come. Until it does, using them inappropriately -- that would be anywhere outside of sending SMS texts among friends -- will remain a stigma among most educated adults.
You can argue all you want about change for change's sake but that ignores reality. As such, it's poor advice not to encourage prospective members of the fire service to learn to write using whole words (spelled correctly) and at least passable grammar when appropriate.