People use whatever tools are the most effective and they have plenty of incentive not to talk publicly about them. I think the era of openness has passed us by. But why does stature matter anyway? If I look at chromium or MSRC bug reports, scarcely any of the submitters are from Europe/US and certainly don't have anything resembling stature. That guy hasn't done anything of note in the field in a long time from what I know, he's kind of boomer (you too, no disrespect).