[DGD] Why use callouts in klib to decay resources?

[Raymond Jennings]

Hey Felix, I was just wondering:

Why were increments to decayed resources (including tick updates)
handled in a callout and not immediately?

I'm asking because I'm making heavy usage of call_limited and it's
building up so many incr_ticks callouts in the rsrc objects that it's
throwing errors about running out of callouts.

I'd like some insight into your original motives so I can decide what
to do about it.