I think that when many other countries have their own customs and traditions; India's should be respected too. Now it a custom for foreign dignitaries to visit the Samadhi and that custom should be upheld to the best possible level. If there are indians who do pay respect to the Samadhi then it is only because of the fact that they are not foreign dignitaries!!! They are indians and feel the spirit of Gandhi in them whereas foreigners should be able to have a glimpse to one of the greatest souls of India.