Regardless of any encryption, wireless can always be disrupted via jamming. Even if management frames were encrypted you can still disconnect devices by jamming the signal.
When talking about home security I doubt the attacker cares much about legality, and detection requires specialised equipment, by the time it is brought in the robbery has already been committed and the attacker is long gone.
Jamming is not as useful as a targeted attack, so this still seems like a defect in the WiFi spec.
For example, an attacker may wish to keep their network working while disrupting others (there is an example of Marriott hotels doing this linked elsewhere in the comments here).
