People have been able to build successful organizations without being abrasive dickheads to their colleagues and subordinates all the time. I think it's a false dichotomy.
Do you have relevant examples (or even better, some statistics)? How do you measure this and how do you know if they were assholes or not? I guess you don't have a record of SLT meetings of large companies (as you have access to the emails between Linus and the maintainers).
Leaders of large companies are _usually_ more aggressive, selfish and less agreeable than average people. This is a well-researched topic (and also makes sense intuitively -- leading a Fortune 500 company comes with so unique perks that there's an immense fight for those roles).
I think that's the point. However, such people "disappear" and end up being less known, even though they had a substantial impact of what they started. This fact then becomes part of entrepreneur folklore, reproducing more and more toxic people, etc, etc.
I'm not sure why it has to be this way or whether it has to be.
