Guild Wars 2

So what effect did Druid have, that called for Spirits to be nerfed?

None.

Spirits weren’t nerfed. They lost the ability to move but had the trait that improved the proc chance made baseline, which was a sizable buff. Then we got a new grandmaster trait that, while lackluster, is an improvement on what we had before. It’s just undertuned currently, and getting a buff in the upcoming patch.

The change to spirits was unrelated to druid. Anet is just trying to make them into what they were originally: Immobile boon machines.