As it happens....yes. Warhammer 40k is dark and imperfect, and unfortunately darkness must sometimes be fought with a little darkness. The Dreadwing were but one example and more or less ceased to exist after the Horus Heresy. The reasons why are unknown but given they were masters of using weapons that could use pure radiation, Phosphex (think white phosphorus mixed with napalm) and various other archaic or extremely devastating weapons, both in man portable and large scale forms, I would say it was because such horrors caused by such weapons were deemed beneath the Dark Angels to cause. Perhaps because they had seen the after effects and resented it, after all, Space Marines are by and large still human.