"I generated a graph from the 400 largest companies by market capitalization. What’s shown here is the largest strongly connected component, which has 212 nodes."
Perhaps technology companies have more interlocked boards because many of them were funded by VCs. 100 years ago, GE would have been connected to all the other Morgan-backed companies.
I don't read Fortune because it seems to be written for middle-school students. I do know that lots of former GE managers are now running their own companies. However, it seems very likely that since most large tech companies were founded in the last 30 years or so, and many of them were funded by a relatively small number of VCs, that those VCs might form a very well-connected network, even if other companies also 'spun off' lots of good managers. I would be surprised if the number of Fortune 500 companies run by GE alumni exceeded the number of Fortune 500 companies funded at some point by Sequoia, Kleiner Perkins, Benchmark, etc.
You and I must be seeing two different things when we look at that graph. I see a pretty standard list of Fortune 500 companies, like Proctor & Gamble or Exxon. Some tech in there to be sure too, but no reason why GE would be excluded. And I'm sure they'd have more nodes than almost any non-tech company, even if your assertion is true.
Perhaps technology companies have more interlocked boards because many of them were funded by VCs. 100 years ago, GE would have been connected to all the other Morgan-backed companies.