Where did they get the meaning of "Sakdalista" (Movement) as "Accused"?
If you are a founder of an organization, Will you use a negative connotation? My gandparents are Sakdalistas and they said Sakdalista means "PURIST"! A very positive word to indicate their intention and objective for Pure liberty from American domination of the Philippines.
I agree with you that a movement would not be likely to give itself a negative name like "the accused." However, I would argue that you are misunderstanding the meaning of this name for this movement/rebellion. From what my father (a native of Laguna Province in Luzon) tells me, this name is not meant to signify that they were the "accused." Instead, it means that they are the ones who are accusing others. Since "sakdal" means "to accuse," it makes sense that "Sakdalistas" would be the ones who accuse. The implication here is that the movement was accusing the government of corruption and of ignoring the needs of the Filipino people.