The previous year, at Chicon II, in a very complicated and political race (see 1953 Site Selection results and The Story Behind Philly in '53), Philadelphia in 1953 narrowly defeated San Francisco in '53 in a vote that one observer described as fans voting with their feet rather than their hearts. So at Philcon II, there was a widespread feeling that San Francisco deserved the 1954 Worldcon (rotation rules had not yet been formalized.)
Unfortunately, there was no San Francisco bid and only one San Francisco fan, Hans Rush, was in attendance — and when the voting started he could not be located. So Don Ford (of Cincinnati!) presented the San Francisco bid. (Remember, in those days the vote was held at the convention during the WSFS Business Meeting which was typically an hour-long item on the single track of program.) Hans had played poker till dawn and went to a nearby hotel to sleep and no one knew where. When he finally showed up he learned that San Francisco had won. Howard Devore, who was in the poker game, probably convinced Don ford to make the bid.