I am only a lay practitioner of Buddhism but from my understanding of Lord Buddha's teaching, it is not possible to make such a judgment on a person, let alone an entire people without having a level of spiritual attainment which provides an undeniable knowledge of such things.
From my own reading of the news, Buddhist news in particular and Buddhist history I have read cases of abuse, violence and greed in every school of Buddhism. In the time of the Buddha, Devadatta was a Buddhist monk who's actions were obviously not correct. It is clearly necessary for these situations to be looked at, talked about and changed when they arise. It would be 'un-Buddhist' to not. But from these instances, can we broadly paint a religion or a people as irrelevant or useless or question the validity of their practice of Buddhism? To honestly do so you would have to apply it to all forms of Buddhism, not just Tibetan Buddhism.
From my understanding of the practice of Buddhism it is correct to calmly face a problem and objectively analyzing and approaching it in a morally correct way. Though this article is of 'opinion', it seems to me to this opinion is in the vein of judging and condemning a generalized people, and not of calmly and honestly approaching an issue and presenting solutions nor of showing compassion toward those who are said to be in the wrong.