Can't edit since I'm posting from my phone, but just wanted to add that I wanted to comment on this issue because I find the rhetoric of "DDs alone are responsible for beating DPS check" very misleading and posing unrealistic expectations when read by people who have no clue about the realities of party DPS in raid fights.
What many people don't seem to understand is, leaving them to DDs alone, without any significant contribution from tanks on healers, really sets the performance standard for DDs to that top 10%ish, while it means healers and tanks are allowed to perform far below average. I would recommend instead that all party members would be asked for at least 50% contribution (in terms of logs numbers).