Calling genuine shit out as such can literally land you in a shitstorm if the person receiving message is of wrong color or sexualual orientation, etc, and decides to make that the point of the story he passes along.
Ranting and swearing is part of who he is personally, but those are not generally required for being a good project leader.
I agree that his other skills are likely more important overall, and there are certainly other ways to be memorable, but I don't think you can discount the contribution of the ranting.
Like others said, his language helps drive the point home and leaves more of an impression. It also humanizes Linus as well.
As far as this particular Torvalds screed goes, it strikes me as measured for him. He is very clear about what he wants more of and what he wants less of. It's the code that is garbage, and he doesn't get overly personal other than to chide Woodhouse for glossing over the quality of Woodhouse's own contributions.
edit: ahh right, "mis-designed by morons" which is pretty inflammatory, and he should do better than that. I suspect he is trying to provoke someone at Intel into explaining their intent. Insult their intelligence, and they'll reveal something about their (possibly sinister) motive.