Maybe the lips start trying to heal "acute inflammation" because certain things like saliva and stress are damaging them? I have trouble believing blood red lips are a good thing, when my lips are in that state they almost have "pressure" in them and feel horrible. On the other hand when my lips are pink they feel and look normal.
I see what you mean about acute inflammation trying to heal the lips but it seems its only trying to heal them because certain factors have made them worse (saliva, stress, something you ate getting absorbed into the lip causing irritation ect ect...)