Well I agree your points and stats. But the number of buses too less than actual demand. And from your own statement you agree Kerala is not operating more buses due to various reasons.
Basically, Kerala people don't support buses - whether IntER-state or IntRA-state. Then, how come other states will run buses. Karnataka & AP/TS states don't have any problem with TN buses, because those state people board buses. But Kerala people are too adamant to board only trains even for a very short distance.