Groundless? Google seems to agree. According to Indian iGyaan, a spokesperson for Mountain View stated that its policies do not allow any content that contains nudity or any sexually explicit material on its Play Store:
“Google Play developer programme policy does not allow content that contains nudity, graphic sex acts, or sexually explicit material. Google has a zero-tolerance policy against child pornography; […] Similarly for Android, we offer content filtering. Google Play requires developers to label their applications according to the Google Play ratings system, which consists of four levels"
If that is indeed true, then the culprit has got to be third-party app stores that are known to host content indiscriminately of its nature – an issue, however, hardly warranting the ban of the world's most popular mobile OS in the third biggest smartphone market.