Based on my experience in grad school, working in industry alongside people that have been through various PhD programs, and working in different domains, I think there are a number of factors at play.
1. Breadth of work experience. People that have worked different jobs in different industries have more perspective and are less likely to be assholes. A career in academia tends to discourage breadth of work experience. The counterpoint are people that have transferred into academia from industry and these people tend to be wonderful to work with.
2. People that are leading research programs are focused on impressing people outside the department in order to acquire research funding and improve their group or school's reputation. They care much less (if at all) about what anyone internal to the department thinks unless that person is above them or critical to their success. This applies to academic programs as well as programs in industry (see point 3).
3. Research programs in industry tend to be shorter-lived than programs in academia, hence people working in industry need to be more flexible and have a broader network of goodwill than academics. Research is not a zero-sum game and if you can help someone with minimal effort that may result in unforeseen rewards many years later.
Almost all of the people I have worked with in both academia and industry I would work with again. I don't think there is a difference in ratio of assholes to non-assholes across academics and industry. The main difference seems to be that people working in academia seem to feel trapped, which certainly intensifies the experience unfortunately.