I think back-in-the-day, the cryptic riddles were a (terrible) way of trying to filter "smart" candidates. The people who could come up with a solution to a problem never before seen. But almost no problems are truly original or new. They are just old problems with new packaging or with new/different requirements. So, usually what you end up testing for is nothing more than "has this person come across something like this before?"
Sometimes you'd get interviewers who were at least smart enough to realize that maybe the most you'd get out of it is "can this person break down a seemingly impossible problem into manageable pieces?" That's fine, but then state that or at least give them something real they'll actually run into if hired instead of trying to estimate how many gas stations there are in LA county in their head.
And while those suck[ed], companies having been doing similarly ridiculous things for a very long time to try and save themselves from hiring the wrong people. IBM's infamous "lunch interview" (false on Snopes, but the concept is true and I've seen played out) or asking candidates to take a personality type test to determine if they'd be a good fit before hiring (yes, I did this once early in my career and would just walk out if asked to do one today).
The most difficult I've found is getting fellow programmers to realize that they _don't_ want to hire another "you." Yes, you're an expert in networking and security. Don't interview for that so you can show off your own skills or "teach" in an interview. Interview _for the position_.
You want a diverse set of knowledge, skills, experiences, communication styles, etc. at your company. And - while it can be scary - you always want to hire people who are better than you (esp. if you're a manager!). But that is so hard to get people to do.