The points would probably take even longer to post if the conductors didn't sort them.

However, the real reason that they take a while to post is simply the fact that there are only a few places where those tickets are sent to be scanned into the computer to record their use. If you happen to be riding a train that ends at one of those few places, then your points will post much faster. Further complicating things is the fact that on long distance trains, the tickets stay on the train from the start of the run to the end of the run.

So if for example you board the Empire Builder in Chicago and ride to say Minneapolis-St. Paul, your ticket remains on that train for another two days until the train reaches Seattle, even though you got off that first night.

And then I believe that the nearest ticket processing center is in San Antonio, Texas. Maybe there is one in LA, but I'm not positive. Either way, the tickets then need to be shipped to one of those locations. So it can easily be 5 or 6 days after you got off the train, before the ticket ever arrives at a processing center.

Then of course with only a few centers, they have mounds of tickets to process at any given time.

E-ticketing when it arrives may well speed up AGR postings, since the conductors will be scanning your tickets, regardless of what type you have. But that's still a few years off at this point I believe.