The terrible reason why the popular is nerfed

No, it isn’t. Ramp Druid has 49.15% winrate in Diamond and 50.27% winrate in Top 1000 Legend (per VS Data Reaper).

There isn’t even a real problem to fix. There’s only the illusory problem of the deck’s popularity. But that’s not the real problem. The real problem is in the heads of the online community, as described in the opening post.