At DefCon, someone did a talk investigating the wireless security of some drones. Some of them had a TELNET port open for anyone to log in. The problem here isn't a lack of formal verification, it's a lack of people caring.
There is only one thing that will fix the problem, and that is when corporations get hit in the wallet for having security flaws, see for example: https://medium.com/@xParXnoiAx/irresponsible-disclosure-52d0...