At a previous company, we also found it to be a usability issue. Customers were confused when they were looking for a place to put their name, but couldn't find one. Incidentally, we encountered the same problem when we removed the "State" field from the address section (we could glean it from the zip).
Sample size of one company, so take this for what it's worth.
The dashed vertical line is the maryland/delaware boundary.
You can see there are people both in maryland, and delaware, who have that zip code. The post office is in seaford, de.
This actually came up in the real world in some elections stuff, because these folks often list their mailing address as in seaford, de, but vote in maryland ;)
I like having the city and state filled from the zip code. That way the user can see that it is being used and will not be confused. Plus, pushing a button to enter text that you normally would have to spend time filling out feels like a reward.
This actually wouldn't surprise me. Similarly, not asking for the card type is confusing to some people (even though the card type is identified in the first characters of the card number).