(1) You don't understand the distinction between having a big ego and being annoying. In this case I don't know what to say, except: thinking you're great doesn't necessitate telling everyone you're great.

(2) You do get the distinction, and you're really arguing that, big ego or small, immodesty is desirable. Again, there's not a lot to say here: it seems possible that Wolfram's success has a lot more to do with creating Mathematica than with telling people he's smarter than they are. If your position is really that being obnoxious (as opposed to merely having self-confidence) is useful, and that we should therefore be obnoxious, then so be it.