ADSB data is really useful when overlaid with other data. It allows investigators to build an early mental model of a flight because too often you have to wait for other data to be downloaded or recovered. It also provides another level of confidence to the data when it is available and provides back-up locational data should that not be recoverable. That it is considered a primary source for armchair investigators means nothing. People appear not to need facts or data before passing opinion and but providing them with some accurate data can at least reduce some of the wildest, most obscure speculation.