Unless you know these people personally, you don't really know what they're like. I know Mark isn't though.
edit: and there are plenty of anecdotal "Kanye is a nice guy when you meet him" stories as well. Evel Knievel sued Kanye and described him as 'vulgar an offensive', after they met he said "I thought he was a wonderful guy and a gentleman":
http://usatoday30.usatoday.com/life/music/news/2007-11-27-ka...
Also read Paul Allen's book -- specifically the part where Gates tried to screw Paul by diluting his stock.
http://www.joelonsoftware.com/items/2006/06/16.html
Certainly feared to some extent.