That would mean foolishness is the most common trait among the people across the subcontinent !!
You have named only the people in India who elect the Congress and the left along with their foolish brothers in Nepal.
What about the people in Jharkhand, Chattisgarh, Orissa, Bihar, U.P, Rajasthan, M.P, Gujarat (yes, even Gujarat) ???
Have the people of the above states emerged from the 'foolishness' so endemic among their counterparts of the other states ?? Have the people of these states become so free of 'foolishness' altogether that their home states have become or are becoming such paragons of equitable development, paradises for commoners with indicators such as levels of literacy, life expectancy, per capita income (after excluding the top 5 percent, say), access to primary health care in rural areas, presence of bonded labour or underpaid labour, access to PDS, hospital beds per thousand people, infant and maternal mortality rates, minimum wages enforcement, land reforms etc. so ascedant that the 'foolish' people who elected their governments in Kerala or WB have been left so pathetically far behind ?
Remember, you who have left 'foolishness' behind - an overwhelming majority of people in each state still is very heavily dependent on the above indicators (and will remain so for a long time to come). Try to find whether there is any foolishness in taking light any of the indicators I mentioned above.