1. Because he talks about all people, instead of dividing them into castes.
2. Because he is hard and absolutely frank when it comes to dealing with terrorism or appeasement of any communities.
3. Because he is a non-corrupted, development oriented and highly determined leader, that is rare in today's politics.
4. Because he a leader with National ambitions.
All these factors clubbed together makes Modi a lethal force who can redefine the shape of Indian politics by uniting the nation and leading it to a development path of glorious heights, which is why the seculars treat him in a scornful way.