Why were prostitutes present in Ayodhya?

In the 9th canto, it is explained that beautiful prostitutes went to welcome Sri Ram on his return to Ayodhya from the war. SB 9.10.51 mentions how everyone was religious and completely happy during his rule. Then why were there prostitutes in his kingdom? Surely the customers of the prostitutes were not religious. Ram Rajya is an example of the best governance by a king, so how was this social ill present then?