Has Zuckerberg not made Facebook searchable (i.e. you can search for content from your Timeline’s history) because:
1)It hasn’t occured to him people want that
2)It hasn’t occured to people THEY want that
3)Software limitations
4)Too expensive
I’d guess 2/3.
They are searchable (at least publicly available one are). I just tested it and got both notes and status updates. Of course, the results were buried very deep into the search results (like page 9+) in a search limited to ONLY Facebook.com, but that could have just been the search term I used.
To pile on, I used to be able to click on “University of ______” or “Washington DC” to see my friends in that network, which was very convenient when it came to inviting people to events, or if I’m going to be in a different city, see who to catch up with. Now that’s gone.