Can't help but think of this article about Musashi
when reading these threads about O-sensei.
The saving grace is that there has been some good scholarship about his life, beliefs, teachings, etc. But with so much BS and "what one wants to believe" being foisted upon him it is often difficult to have an intelligent conversation about it. Especially when entire generations were given the more "colorful" versions of his life.
My humble opinion? Great martial artist. Interesting fella when it comes to all the other stuff. I'm just focusing on the martial art part hoping to get what I can from that... I'll leave the rest to those who have actually studied these things.
I'll also add that I think many of the negative reactions were due to the rather "authoritative" statements and subsequent "defensive" sounding replies. There comes a point when "if it walk like a duck" kind of comments are really not helpful especially if you've only seen one or two ducks. There is a lot to learn and read about O-sensei. That is always a good place to start.