The first (big) AI winter he refers to was in the mid 70s. The 80s (mid/end) AI winter have had an effect on private companies, but it was also mostly because

The first (big) AI winter he refers to was in the mid 70s. The 80s (mid/end) AI winter have had an effect on private companies, but it was also mostly because of government funding was reduced/eliminated, where their revenue was coming from. Much of the revenue of the computer hardware and software companies in the 80s AI bubble was coming from government funding, like the Strategic Computing Initiative and the Strategic Defence Initiative ("Star Wars"), both running from 1983 until 1993, with various levels&aims of funding. That was a part of the effort to win the cold war (here by investing huge amounts of money into modern weapons & defense systems, which meant also into computing and AI) with the Soviet Union , which eventually collapsed, end 80s - early 90s. Also many of the promises of the AI technology did not materialize -> the private sector did not take over the funding.