"If in the eyes of the USPTO, Patriot's argument on 584 is not very strong, why would Sony, HP, and the others settle with Patriot?"

First, welcome aboard.

To answer your question, IMO, couple reasons. First, IMO the "584 isn't the end all be all for Patriot. PTSC has two other patents in question, the "336 and "148 which IMO are much more important than the "584, and much more widely used. These two are also being reexamined by the USPTO.

Second, I have to figure that companies like Sony, HP, and others, had their legal resources look at the patents, identify the risk, and came to the conclussion that settling was much less riskier than pursuing legal action.

IMO we will have a much clearer picture by year end. Hang in there. Good luck to you, me, us, and all longs.