He absolutely drives to the hoop less, and that includes big games.
The reason? Either because he's gotten lazy or has false confidence in his still-feeble jumper.
I can't read his mind, so I don't know exactly what the cause is, but if you replaced all of the terrible mid range shots Rondo took this past season with drives to the basket, Rondo would have resembled a better version of his 2007 self, and would have been much more efficient, and possibly even an MVP candidate.
Rondo's decision to sit back and put up bad shots that he can't make is the reason why he had his worst year since 2007.