They're smart enough to realize that the oil money isn't going to last forever and they'd better start diversifying. This will require them to moderate themselves a bit. And, really, many Saudis were growing tired of the rigid Wahhabist rules that hobbled their day-to-day lives and are welcoming the Crown Prince's reforms.
The interesting thing is that beginning in the 19th century, the House of Saud and the Wahhabi were a symbiotic pair. It lasted through the revolts of 1920s, through the oil boom, and now we have something totally different.