Why do people cancel their Fluther account? Why not just stop participating?

I can only speak for myself, but if I got tired of Fluther, I would just stop showing up. However, it is highly likely that I would keep the account active just to have the option to return. People who checked my profile would notice that my last visit was a long time ago.
Occasionally, I have clicked on an avatar in a thread to see what was new with a particular Flutherite.
And low and behold, they are gone. Just…gone.
It seems like not showing up, and canceling are two different things.
The first is sort of ambiguous, the second is a statement.
Why do you think people cancel instead of just not showing up?