By saying and showing that Dorje Shugden practice is mainstream is not to imply that minority practice should not be accorded recognition and accepted. It is rather to counter the claim by the Dalai Lama faction that Dorje Shugden practice is small. Hence, by proving that it is Not small, their logic is debunked.
Their logic is that a small religious group does not deserve protection, and therefore can be persecuted.
This logic is debunked by showing that any religious group, big or small, deserves protection, and that people engaged in the persecution of any religious group, big or small, such as the evil dalie lame of Tibet, are sociopaths, and criminals against humanity deserving due punishment.
Trying to debunk the evil dalie and his minions with the argument that Shugdenpas are a big religious group only reinforces the dalaite logic that small religious groups do not deserve protection, and therefore can be persecuted.
Now, of course, showing that Shugdenpas are a huge religious group in Tibet and abroad does serve the purpose of showing that the evil dalie and his Tibetan and Western minions are compulsive liars, as it is the case with socioptahs and criminals in general.