CIO is now a mature position
In the past, IT was magic stuff. To be a CIO all you had to have was the desire to put on a suite and claim fat cheque while the BOFHs did all the hard work. Any cock ups could be blamed on fast changing and unpredictable technology.
Now that the tech is largely stabilised, and the people you deal with (ie. VPs and boards) are getting a grip on how IT works, it is harder to just bullshit your way through your job. Competence vs incompetence is getting obvious. Hopefully that means many of the people who just used bullshit to secure their position will be flushed out and eliminated.