If it becomes acceptable to mandate that a lock is sold with a gun, it might soon become acceptable to mandate that the locks must be used at all times. After all, of what use is a lock if no one uses them?
(Consider seat belts, they were first optionally installed, and then mandatorially installed in vehicles, but optional to wear. Since then, they have become mandatory for kids, then for everyone in the front seat, but not as a primary offense, but now that and mandatory child seats are primary offenses in Colorado. "Slick it or ticket.")
We know too much about the gun grabbers to believe that trigger lock requirements will stop at them being merely madated, for sale only, for new handguns only.
You make a good point. I wouldn't worry as long as gun locks weren't made mandatory. The key to all this is having the right faces on the High Court.
The seat belt analogy is on the money!