Your stats are interesting but they don’t account for people that may have spent a long time trying to beat those raid bosses. Raid bosses give you an end game goal to acheive. To try for anyhow. You can sort of measure your success by how well you can do against an “invincible”.
And even amongst those who do manage to beat some raid bosses, even fewer beat the raids from the pirate DLC, or hammerlock. Because they aren’t that well done. Too cheap. Hyperius isn’t too bad though. Acid pool guy was a jerk. Hammerlock raids I don’t know very well. Pyro pete, the dragons and terra were my favorites because I felt their fights were more balanced. I don’t know the HH bosses that well.
My point is, some of the raids were hit or miss. So more is definitely better in case some of them are too hard and they provide different types of challenges.
ALSO, the surivivability of our classes in TPS is better than in BL2. IF we could go fight some of the raids in BL2 as the classes from TPS we probably would see higher kill stats. So it’s a real shame that we don’t have more raids to test our mettle against.