The excuse is that they are not heroic or mythic raiders. 400k at 895 ilvl is parsing blue or higher.
Here's Garothi Worldbreaker normal at 909 ilvl (the lowest recorded on WoL) and 40% bracket. 400k is about average. You're talking about people with gear 20 ilvls lower than that and expecting them to do twice as much damage.
https://www.warcraftlogs.com/statist...t=1&dataset=40
Your "pass rating" of 700k DPS is actually a 90% or higher parse at 909 level. It would be literally impossible at 890.
If you don't like LFR, that;'s fine. But don't make shit up or expect people to have the same competency as Mythic raiders in order to complete it.