Interesting question. My feeling when I first read your post was the latter. Pondering the matter further I can see a case for the former. Perhaps it's chicken and egg, so to speak. I really don't know. I'll go with my gut feel and say the latter. I never knew WPC was so highbrow!!!
High brow?..nice.. It could as you stated be the chicken and the egg, it is definitely a continuing pattern Im observing. These habits will continue especially among the younger generations who have a decreasing volume of vocabulary in daily conversation let alone quick SMS. It could be that through SMS our language is evolving?