This.. if you can't make it in time, you're just not good enough. If you're top dps in your guild, try to change guild for better one or be fine with 6/8
Raid aren't so hard, we are now rank 600 +/- and we are just semi-hardcore. I switched guild, I was in one where we couldn't finish Jaina before 8.2, now my old guild is 4th week on Zaqul and still too far from kill.
My friend also in semi-hardcore guild finished raid quite fast around rank 80, and they are not tryhard, they raid 12 hours per week (4 days).
It's hardest content, it's not meant to be for everyone.