I don't pay attention to my own counts but I assume acconts were deactivated. People don't tend to clean out profiles they don't like.

No, unless your actual watcher count number is falling
I reference the watcher number at the bottom of the page.
The one at the top this last week on my profile has dropped significantly, along with comments and faves. I'm thinking old things are getting flushed out. As I've seen no actual changes so far.
The top watcher counter has dropped while the bottom one that actually shows how many you have hasn't changed.
I go slep. Too tired to be coherent

The watchers counter in my profile hasn't decreased (which is the important number).
I guess you mean the notification watchers number. Mine has decreased like +100 in one week.
As Dragoneer told me on Twitter, it can be deleted accounts that took time to be processed.

Welcome to ram ranch