I'm fascinated that there are people on HN who have not disabled GateKeeper. I'm not sure i've used a machine since it was added where i haven't disabled it within an hour of setting up a machine.
$ spctl --assess --verbose /Applications/Sublime\ Text.app
/Applications/Sublime Text.app: accepted
source=Developer ID
Or have you downloaded a special version from a Chinese file sharing website? :)No.
Every unsigned app you download needs to be whitelisted. Right click the app, click open. It will remember your choice and whitelist the app forever more.
Solving the unsigned app problem by silently ignoring clearly invalid signatures is like solving an ant problem by burning down your house.