The point is how many news agencies, blogs, and pundits quote these same analysts day after day without questioning their track record, motives, or experience. I think its good to have someone calling them on their "expertise" from time to time.
The difference between Gruber and Williams?
Gruber makes very clear (in his columns and Twitter feed) that he is brutally honest about his subjectivity on all issues. Willams pretends he is "objective", the same way Paul Thurrott, John Dvorak, Rob Enderle and Joe Wilcox all claim to be "objective" about Apple specifically, and other issues in general. Who has jumped the shark?