I remember an article I've read around 1983 when this regulation was first introduced. Some plane taking off suffered from instrument interferences at take off,

I remember an article I've read around 1983 when this regulation was first introduced. Some plane taking off suffered from instrument interferences at take off, and trouble ceased when they asked some guy to turn off his "Game & Watch". Though they tried hard to reproduce the problem, they couldn't, but the rule nonetheless applies "just in case".