I doubt it's any more or less taboo than speculating whether he died from a car accident, FSB plot, or unrequited love of Kim Kardashian. Without substantiation, it's not very productive discussion, especially for those who are curious about his life's achievements. Otherwise, suicide and depression have been not uncommon topics of discussion:

https://hn.algolia.com/?query=suicide&sort=byPopularity&pref...

https://hn.algolia.com/?query=depression&sort=byPopularity&p...