I assume you meant to say Druids, not Shamans. The reason for that is it's not an obvious thing for the eye:
- It's a passive proc, that people don't even track it, because it's not something you can control.
- In the past we didn't have the tools to check or notice it. In the past we couldn't check buff uptimes on Skada/Details, those came in play later.
- Same for Logs, they arrived later but even Logs are not very easy to navigate through for a lot of people.
- And of course, because it was never something that noticeable to "break" the game, therefore most people haven't noticed it. And I want to give logical example here - it was million times harder for someone that wasn't playing a Balance Druid to notice it, because from the POV of anyone else, it literally makes no difference, no one would notice a Balance Druid for being an outlier in DPS or would notice if they are going out of mana or not. But if Boomies have noticed it, I would say the reason they didn't report it was because they wanted to continue to have fun and don't give up on something that they got used for so long.