Is this just a matter of having the wrong search terms, or is there a reason why there are no SMD AC connectors. They all seem to be thru-hole, like this:
I can imagine several benefits to an all SMD power supply board, such as eliminating spacers and mounting directly to a metal back plate (if one uses tented vias and perhaps a layer of kapton-like film between the board and plate), potentially leading to improved ruggedness, thermal performance (chassis as heatsink, backplate allowing for greater heatsink mounting forces), and compactness.
The only reason I can think of is mechanical strength, but that seems like a non-issue for most applications where the connector is firmly mounted to the chassis and there are no plugging forces transferred to the PCB.