Traditional locks are more like suggestions, and have a well known attack called "lockpicking", that is easy to learn. I doubt smart locks will be less secure than that.
Don't forget the other major characteristics of network-connected gear; it's not just that a lock can be hacked remotely, but that all of them can be hacked at once, or even just all left accidentally unlocked because someone screwed up at Cloud Central.
The real problem with all this network connected stuff isn't even the new failure modes per se... it's the correlated nature of the new failure modes. (You know you're a Real Systems Engineer if something inside of you just screamed in terror.)
Still leaves concern for DOS and privacy attacks.