Arriving/Leaving on a single ToDo within context
 

I have a question because I think this feature is implemented wrong or I'm using/holding it wrong.

Why does Omnifocus only allow "when arriving" or "when leaving" set on a context (with geolocation) but not on a single ToDo?

I have a context "work" and "home".

I want to pick up my suit from laundry after I have left work.
I want to inform my superior about something when I arrive at work.
I want to care about some bureaucratic stuff after I arrive at home.

I think it's not very convenient to create two context "Arriving at work", "Leaving work", "Arriving home", "Leaving home" and so on.

Well, an underlying notion is that for most actions, the context is going to be used more than once. Truly "one-off" actions are not so conveniently handled by this choice, but for most of us, the bulk of the work happens in the same collection of places, with the same collection of people, using the same collection of tools. It ends up being less effort to make one "arriving at work" context and assign that to each task that needs to be done when arriving at work than to create an "arriving at work" notification each time you come up with a task that needs to be done when you arrive at work. Also, it is much easier to see (and perhaps change) all of your tasks which need to happen when you arrive at work, rather than some sort of search for tasks which need to take place when arriving at a given address.