I find the very concept of dual citizenship to be repugnant. A dual citizen has divided loyalties to two different countries. Far fetched, but on which side would a dual citizen's loyalties lie if the two countries he belongs to are at war with each other ?
I prefer to pledge my allegiance to one country, come what may, and only if f or whatever reason, such as immigration to improve my life prospects, I decide to accept the citizenship of another country, I will abandon my former citizenship. India is absolutely correct in requiring those who take citizenship in another country to give up Indian citizenship. This is what any self respecting country will do. I believe the trend towards dual citizenship started with the Israelis for which the USA made a special exception because they are hand in glove with the Israelis anyway. For all practical purposes, Israel may as well be the 51st State of the USA. Does Canada allow its citizens to hold dual citizenship ?. Citizens of the USA by law are automatically considered to have renounced US citizenship if they acquire the passport of another country, or join the Armed Forces of another country.
