It’s not misleading.
Here’s an old thread I pulled together back then
The percentages are Algalon kills / total parses in Ulduar of that spec (any boss), so it’s normalized to the people actually still raiding.
Ret was a noticeable step below fury, which was around the lowest spec still part of the rest of the pack.
You were just significantly less likely to see an Algalon kill as a paladin DPS than any other class before the buffs.