And sometimes being personally disrespectful yields better results. Which is, after all, what one wants out of a software project: results, not happy feelings.
I think we'd all like to be personally respected (I know I would). But I also think that almost all of us have done things which aren't respectable (I know I have); and I believe that at least for some people, the shame of public disrespect is part of the learning experience involved in not doing it again.
If this atmosphere of harsh personal criticism does yield better results, then it's necessary. I'm reminded of the old adage, 'if you can't stand the heat, get out of the kitchen.' Heat is necessary to cook (a kitchen in summer is miserable, particularly without air conditioning); interpersonal heat may be necessary to produce better software.
I myself don't do so well in an atmosphere of intense personal criticism, and have great difficulty giving it, but I consider those my own personality flaws.