I use the word "demanding" for a reason. These aren't requests or advice, but demands. These people will quote lamas such as HH Karmapa completely out of context in order to "prove" that they have the right to demand Tibetans follow their ideas of political activism. In addition, these are almost uniformly people who have few, if any, deep connections within the Tibetan community. Needless to say, not one of them could communicate successfully in Tibetan if they tried. None of them, to my knowledge, had ever set foot in Tibet.
But even if they had, even if they had lived in Tibetan communities for years, spoke fluent Tibetan, had dozens of very close Tibetan friends who were practically family: they would still not have the right to demand Tibetans conform to their ideas of correct activism. How many times does it need to be said? Tibet is a Tibetan issue! Tibetans are the only ones who should decide how to take it forward. We are supporters. Our job is to support.
In a case of violence, such as a bombing killing civilians, outsiders would have the right to object to the violence and stand in defense of the victims. However, in the case of immolations the victims are the perpetrators. These young men and women have decided to take their own lives in a form of protest that shares a long history across many cultures.
Does that mean outsiders should condone the immolations? Not necessarily. Tibetans are the ones who decide how to take their activism forward. We, as foreigners, can try to be respectful supporters and voice our opinions, but we can make no demands in either direction whether saying "you must do this" or "you must not do this." And everyone, Tibetan or foreigner, has the right to their own opinion. Therefore, it is absolutely okay to choose not to condone the immolations. But the difference is this: If we, as foreign supporters, do not agree with the actions of Tibetans; we must recognize that it is not our country, not our lives and therefore not our choice. As abhorrent as one might find the immolations, and as many do, we are not the ones who need to deal with the Chinese on a daily basis.
So it comes down to this: We can accept that we support Tibetans and their rights to decide their own future for their country and their rights to decide how to achieve that, even if we find a certain tactic distasteful, or we can walk away and give up our self declared, innacurate title of "supporter".
If you truly believe that your right to object is more important than the Tibetan people's right to self determination, whether for their country as a whole or even just in terms of deciding how to protest, then you object to Tibetans' rights to decide for themselves. The whole goal is for Tibetans to regain that right to self governance. If you object to that, you have no business here.