You are 100% on target. The only terrorists the Saudis have a problem with are the ones that want to take out the Saudis.
Which makes them no different than anybody else. I mean really, how concerned was America about terrorism back when most terrorists were tied to the IRA and blowing up British stuff and Arab terrorists were only gunning for Israel? Most nations are just like most people, that which isn’t affecting them directly doesn’t matter. Of course there are exceptions at both levels, which is why even if a country doesn’t care individuals in that country just might.