This property probably has more Platinum guests most nights than they have suites and rooms on the Club Floor. Therefore, many Platinums are probably upgraded to the Starwood Preferred Guest Floor (14th floor and perhaps others). Since many of the guests on the 14th floor have complimentary Club access, through their Platinum status, the sign is a friendly way of reminding those guests of the location of the Sheraton Club. From my own experience, frequent travelers staying in a different hotel each night appreciate this.

The sign is not there to taunt someone who does not have complimentary access.