The thing is Saudi Arabia has tried to diversify its economy many times before... it hasn't gotten it done. They have a huge gut of workers entering the workforce soon and it seems they are they're not educated enough to compete.
A nice man I met from SA noted that education in SA was still heavy on religion, and all his friends aspired to comfortable government jobs that are easy, and pay well, as that has been the place to be for decades.
I'm not sure you can fix that in say 20 years....