Gratitude is a big word for those who does not have it.
The entire Western and probably the world for those who rely on Je Tsongkhapa's doctrine, owes gratitude to all the Gelug Lamas of old, all of them practiced Dorje Shugden without a doubt. All the Gelug lamas came to the West with probably two suitcases and see what they accomplished so far. All the Gelug lamas who made a mark on the world had been students of Trijang Lama, people can try to deny it but that is the truth. NKT who kept their samaya with Lama Dorje Shugden, Tirjang Rinpoche carries on from strength to strength whereas the Maitreya Project and the heir to FPMT is at tenter hooks so what will happen to FPMT then?
How can the ingratitude to Dorje Shugden and one's Gurus bring success and growth for one's spiritual organisation?