We should protest about the visa mailing back

Before 9.11, you go for interview and if passed, you can get the visa immediately, no mailing back, no waiting time, no picking up. I do not understand why the technology goes back in time right now.
The mailing back process takes 3-4 business days. Even though the China Postal office works in weekends, they still say that Saterday and Sunday are not business days.
Plus these additional days, the checking process is even longer.
If the US embassy want this additional 30RMB, they can just add it to the visa application fee. Why bother so much?