Even with whales, martingale is devastating. It will only take some series of loses before the whale player runs out of money. So martingale isn't only devasting for low bankroll player but also devastating to those who have a huge bankrolls.
I don't know why some members refuse to understand/believe that the martingale strategy won't work even for players who have huge bankrolls! I provided a link to an article, in a previous reply, which explains with examples how a small number can become enormous after you double it few times.