Certainly GM venturing into every market feasable has earned them GREATER PROFITS.
Xbox360 hardware is VERY PROFITABLE.
I have a hard time believeing Apple sticking their fingers into every market possible would make them "more successful". Apple's whole business strategy is Quality over Quantity. This is 100% counterproductive.
Blizzard games are quite successful, no? They don't make every genre of game possible, which is how EA's reputation has gone to the shitter.
Notice a trend?
by "Huge press conferences", you mean a developer conference right? WWDC....
And so what? They OCASIONALLY have a conference. What company doesn't? Microsoft? Intel? AMD?
Last I checked, this was quite common. Even the white house has press conferences!
Blast, they must all be evil for announcing new products, when people interested decide to listen! EVIL I SAY!