Sharia doesn’t have its sanctions from Quran and learned Muslims are shy about its legitimacy, let alone fitting their life into it. Yet others are obsessed in its favor, but Sharia cannot be owned by passion alone.
Other than given the scriptures, it is generally the popular thought forces of masses (right or wrong) that act upon society to accept or reject norms (right or wrong) for its people. To confirm this theory, take the case of interest which is unlawful, but ask why it is so prevalent across all Muslims societies everywhere. On similarly basis, sharia cannot take its root without its enforceable power caused by forces of popular thinking in its favor.
If popular thinking cannot be endemic favoring Sharia, the only option left is emergence of some dependent physical forces in society by chance (like Ziaul Haq) who may do the job. But its dogmatic outcome may be worse than Sharia can take it.