Al Qaeda has a major beef with the Saudis, too.
There are many similarities with the ideology, but the difference is that the official Saudi version exists as a way of propping up the Saudi dynasty as "protectors of Islam", while the terrorist groups object to some of the more political compromises the Saudi regime has made. The Saud family created an aliiance with Wahabbi clerics to consolidate power, but they also decided to permit Shia pilgrims to visit Mecca because they didn't want to alienate the elites of the Hejaz region, where Mecca is located.
Most of the 9/11 hijackers came from Saudi Arabia, and there's a history of events like the Grand Mosque seizure in the 70s, as well as assassinations due to dynastic struggles (and the Saudi royal family is ridiculously large).
I'll qualify things by adding that I'm not an expert on any of this, and most of this information I have gotten from reading articles online, rather than any full length books on the subject.
The Saudi regime spearheaded a peace initiative with Israel (which Netanyahu stupidly rejected) because they're so freaked out about ISIS. It's actually one of ISIS's chief targets. If they succeeded in getting control of Mecca and Medina, they'd gain a lot more legitimacy.